Update Prometheus metrics tracking (#459)

Signed-off-by: Andrew Morgan <andrewm@matrix.org>
This commit is contained in:
Andrew Morgan 2018-05-23 15:42:08 +01:00 committed by GitHub
parent 93a6178d45
commit c238048599
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GPG Key ID: 4AEE18F83AFDEB23
155 changed files with 30171 additions and 12 deletions

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@ -40,9 +40,20 @@ import (
"github.com/matrix-org/dendrite/clientapi/jsonerror"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/prometheus/client_golang/prometheus"
log "github.com/sirupsen/logrus"
)
var (
// Prometheus metrics
amtRegUsers = prometheus.NewCounter(
prometheus.CounterOpts{
Name: "dendrite_clientapi_reg_users_total",
Help: "Total number of registered users",
},
)
)
const (
minPasswordLength = 8 // http://matrix.org/docs/spec/client_server/r0.2.0.html#password-based
maxPasswordLength = 512 // https://github.com/matrix-org/synapse/blob/v0.20.0/synapse/rest/client/v2_alpha/register.py#L161
@ -50,6 +61,11 @@ const (
sessionIDLength = 24
)
func init() {
// Register prometheus metrics. They must be registered to be exposed.
prometheus.MustRegister(amtRegUsers)
}
// sessionsDict keeps track of completed auth stages for each session.
type sessionsDict struct {
sessions map[string][]authtypes.LoginType
@ -665,6 +681,9 @@ func completeRegistration(
}
}
// Increment prometheus counter for created users
amtRegUsers.Inc()
return util.JSONResponse{
Code: http.StatusOK,
JSON: registerResponse{

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@ -30,6 +30,8 @@ import (
"github.com/matrix-org/dendrite/publicroomsapi"
"github.com/matrix-org/dendrite/roomserver"
"github.com/matrix-org/dendrite/syncapi"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/sirupsen/logrus"
)
@ -66,16 +68,21 @@ func main() {
httpHandler := common.WrapHandlerInCORS(base.APIMux)
// Set up the API endpoints we handle. /metrics is for prometheus, and is
// not wrapped by CORS, while everything else is
http.Handle("/metrics", promhttp.Handler())
http.Handle("/", httpHandler)
// Expose the matrix APIs directly rather than putting them under a /api path.
go func() {
logrus.Info("Listening on ", *httpBindAddr)
logrus.Fatal(http.ListenAndServe(*httpBindAddr, httpHandler))
logrus.Fatal(http.ListenAndServe(*httpBindAddr, nil))
}()
// Handle HTTPS if certificate and key are provided
go func() {
if *certFile != "" && *keyFile != "" {
logrus.Info("Listening on ", *httpsBindAddr)
logrus.Fatal(http.ListenAndServeTLS(*httpsBindAddr, *certFile, *keyFile, httpHandler))
logrus.Fatal(http.ListenAndServeTLS(*httpsBindAddr, *certFile, *keyFile, nil))
}
}()

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@ -134,7 +134,6 @@ func (b *BaseDendrite) CreateFederationClient() *gomatrixserverlib.FederationCli
// ApiMux under /api/ and adds a prometheus handler under /metrics.
func (b *BaseDendrite) SetupAndServeHTTP(addr string) {
common.SetupHTTPAPI(http.DefaultServeMux, common.WrapHandlerInCORS(b.APIMux))
logrus.Infof("Starting %s server on %s", b.componentName, addr)
err := http.ListenAndServe(addr, nil)

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@ -10,7 +10,7 @@ import (
"github.com/matrix-org/util"
opentracing "github.com/opentracing/opentracing-go"
"github.com/opentracing/opentracing-go/ext"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
// MakeAuthAPI turns a util.JSONRequestHandler function into an http.Handler which checks the access token in the request.
@ -36,7 +36,7 @@ func MakeExternalAPI(metricsName string, f func(*http.Request) util.JSONResponse
h.ServeHTTP(w, req)
}
return prometheus.InstrumentHandler(metricsName, http.HandlerFunc(withSpan))
return http.HandlerFunc(withSpan)
}
// MakeInternalAPI turns a util.JSONRequestHandler function into an http.Handler.
@ -62,7 +62,7 @@ func MakeInternalAPI(metricsName string, f func(*http.Request) util.JSONResponse
h.ServeHTTP(w, req)
}
return prometheus.InstrumentHandler(metricsName, http.HandlerFunc(withSpan))
return http.HandlerFunc(withSpan)
}
// MakeFedAPI makes an http.Handler that checks matrix federation authentication.
@ -87,8 +87,7 @@ func MakeFedAPI(
// SetupHTTPAPI registers an HTTP API mux under /api and sets up a metrics
// listener.
func SetupHTTPAPI(servMux *http.ServeMux, apiMux http.Handler) {
// This is deprecated.
servMux.Handle("/metrics", prometheus.Handler()) // nolint: megacheck, staticcheck
servMux.Handle("/metrics", promhttp.Handler())
servMux.Handle("/api/", http.StripPrefix("/api", apiMux))
}

12
vendor/manifest vendored
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@ -123,7 +123,7 @@
{
"importpath": "github.com/matrix-org/dugong",
"repository": "https://github.com/matrix-org/dugong",
"revision": "a012152b8769963afc822a9af7a3eceac4d776e8",
"revision": "ea0a4690a0d5b414a18dbb06cf6153309a2d0528",
"branch": "master"
},
{
@ -209,9 +209,15 @@
"path": "/difflib"
},
{
"importpath": "github.com/prometheus/client_golang",
"importpath": "github.com/prometheus/client_golang/prometheus",
"repository": "https://github.com/prometheus/client_golang",
"revision": "c317fb74746eac4fc65fe3909195f4cf67c5562a",
"revision": "c51dc758d4bb30acacbef9eaa2b774969a135086",
"branch": "master"
},
{
"importpath": "github.com/prometheus/client_golang/prometheus/promhttp",
"repository": "https://github.com/prometheus/client_golang",
"revision": "c51dc758d4bb30acacbef9eaa2b774969a135086",
"branch": "master"
},
{

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@ -0,0 +1,109 @@
## 0.8.0 / 2016-08-17
* [CHANGE] Registry is doing more consistency checks. This might break
existing setups that used to export inconsistent metrics.
* [CHANGE] Pushing to Pushgateway moved to package `push` and changed to allow
arbitrary grouping.
* [CHANGE] Removed `SelfCollector`.
* [CHANGE] Removed `PanicOnCollectError` and `EnableCollectChecks` methods.
* [CHANGE] Moved packages to the prometheus/common repo: `text`, `model`,
`extraction`.
* [CHANGE] Deprecated a number of functions.
* [FEATURE] Allow custom registries. Added `Registerer` and `Gatherer`
interfaces.
* [FEATURE] Separated HTTP exposition, allowing custom HTTP handlers (package
`promhttp`) and enabling the creation of other exposition mechanisms.
* [FEATURE] `MustRegister` is variadic now, allowing registration of many
collectors in one call.
* [FEATURE] Added HTTP API v1 package.
* [ENHANCEMENT] Numerous documentation improvements.
* [ENHANCEMENT] Improved metric sorting.
* [ENHANCEMENT] Inlined fnv64a hashing for improved performance.
* [ENHANCEMENT] Several test improvements.
* [BUGFIX] Handle collisions in MetricVec.
## 0.7.0 / 2015-07-27
* [CHANGE] Rename ExporterLabelPrefix to ExportedLabelPrefix.
* [BUGFIX] Closed gaps in metric consistency check.
* [BUGFIX] Validate LabelName/LabelSet on JSON unmarshaling.
* [ENHANCEMENT] Document the possibility to create "empty" metrics in
a metric vector.
* [ENHANCEMENT] Fix and clarify various doc comments and the README.md.
* [ENHANCEMENT] (Kind of) solve "The Proxy Problem" of http.InstrumentHandler.
* [ENHANCEMENT] Change responseWriterDelegator.written to int64.
## 0.6.0 / 2015-06-01
* [CHANGE] Rename process_goroutines to go_goroutines.
* [ENHANCEMENT] Validate label names during YAML decoding.
* [ENHANCEMENT] Add LabelName regular expression.
* [BUGFIX] Ensure alignment of struct members for 32-bit systems.
## 0.5.0 / 2015-05-06
* [BUGFIX] Removed a weakness in the fingerprinting aka signature code.
This makes fingerprinting slower and more allocation-heavy, but the
weakness was too severe to be tolerated.
* [CHANGE] As a result of the above, Metric.Fingerprint is now returning
a different fingerprint. To keep the same fingerprint, the new method
Metric.FastFingerprint was introduced, which will be used by the
Prometheus server for storage purposes (implying that a collision
detection has to be added, too).
* [ENHANCEMENT] The Metric.Equal and Metric.Before do not depend on
fingerprinting anymore, removing the possibility of an undetected
fingerprint collision.
* [FEATURE] The Go collector in the exposition library includes garbage
collection stats.
* [FEATURE] The exposition library allows to create constant "throw-away"
summaries and histograms.
* [CHANGE] A number of new reserved labels and prefixes.
## 0.4.0 / 2015-04-08
* [CHANGE] Return NaN when Summaries have no observations yet.
* [BUGFIX] Properly handle Summary decay upon Write().
* [BUGFIX] Fix the documentation link to the consumption library.
* [FEATURE] Allow the metric family injection hook to merge with existing
metric families.
* [ENHANCEMENT] Removed cgo dependency and conditional compilation of procfs.
* [MAINTENANCE] Adjusted to changes in matttproud/golang_protobuf_extensions.
## 0.3.2 / 2015-03-11
* [BUGFIX] Fixed the receiver type of COWMetric.Set(). This method is
only used by the Prometheus server internally.
* [CLEANUP] Added licenses of vendored code left out by godep.
## 0.3.1 / 2015-03-04
* [ENHANCEMENT] Switched fingerprinting functions from own free list to
sync.Pool.
* [CHANGE] Makefile uses Go 1.4.2 now (only relevant for examples and tests).
## 0.3.0 / 2015-03-03
* [CHANGE] Changed the fingerprinting for metrics. THIS WILL INVALIDATE ALL
PERSISTED FINGERPRINTS. IF YOU COMPILE THE PROMETHEUS SERVER WITH THIS
VERSION, YOU HAVE TO WIPE THE PREVIOUSLY CREATED STORAGE.
* [CHANGE] LabelValuesToSignature removed. (Nobody had used it, and it was
arguably broken.)
* [CHANGE] Vendored dependencies. Those are only used by the Makefile. If
client_golang is used as a library, the vendoring will stay out of your way.
* [BUGFIX] Remove a weakness in the fingerprinting for metrics. (This made
the fingerprinting change above necessary.)
* [FEATURE] Added new fingerprinting functions SignatureForLabels and
SignatureWithoutLabels to be used by the Prometheus server. These functions
require fewer allocations than the ones currently used by the server.
## 0.2.0 / 2015-02-23
* [FEATURE] Introduce new Histagram metric type.
* [CHANGE] Ignore process collector errors for now (better error handling
pending).
* [CHANGE] Use clear error interface for process pidFn.
* [BUGFIX] Fix Go download links for several archs and OSes.
* [ENHANCEMENT] Massively improve Gauge and Counter performance.
* [ENHANCEMENT] Catch illegal label names for summaries in histograms.
* [ENHANCEMENT] Reduce allocations during fingerprinting.
* [ENHANCEMENT] Remove cgo dependency. procfs package will only be included if
both cgo is available and the build is for an OS with procfs.
* [CLEANUP] Clean up code style issues.
* [CLEANUP] Mark slow test as such and exclude them from travis.
* [CLEANUP] Update protobuf library package name.
* [CLEANUP] Updated vendoring of beorn7/perks.
## 0.1.0 / 2015-02-02
* [CLEANUP] Introduced semantic versioning and changelog. From now on,
changes will be reported in this file.

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@ -0,0 +1,18 @@
# Contributing
Prometheus uses GitHub to manage reviews of pull requests.
* If you have a trivial fix or improvement, go ahead and create a pull request,
addressing (with `@...`) the maintainer of this repository (see
[MAINTAINERS.md](MAINTAINERS.md)) in the description of the pull request.
* If you plan to do something more involved, first discuss your ideas
on our [mailing list](https://groups.google.com/forum/?fromgroups#!forum/prometheus-developers).
This will avoid unnecessary work and surely give you and us a good deal
of inspiration.
* Relevant coding style guidelines are the [Go Code Review
Comments](https://code.google.com/p/go-wiki/wiki/CodeReviewComments)
and the _Formatting and style_ section of Peter Bourgon's [Go: Best
Practices for Production
Environments](http://peter.bourgon.org/go-in-production/#formatting-and-style).

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@ -0,0 +1,8 @@
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@ -0,0 +1,201 @@
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@ -0,0 +1 @@
* Björn Rabenstein <beorn@soundcloud.com>

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@ -0,0 +1,23 @@
Prometheus instrumentation library for Go applications
Copyright 2012-2015 The Prometheus Authors
This product includes software developed at
SoundCloud Ltd. (http://soundcloud.com/).
The following components are included in this product:
perks - a fork of https://github.com/bmizerany/perks
https://github.com/beorn7/perks
Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
See https://github.com/beorn7/perks/blob/master/README.md for license details.
Go support for Protocol Buffers - Google's data interchange format
http://github.com/golang/protobuf/
Copyright 2010 The Go Authors
See source code for license details.
Support for streaming Protocol Buffer messages for the Go language (golang).
https://github.com/matttproud/golang_protobuf_extensions
Copyright 2013 Matt T. Proud
Licensed under the Apache License, Version 2.0

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@ -1 +1,94 @@
See [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus).
# Prometheus Go client library
[![Build Status](https://travis-ci.org/prometheus/client_golang.svg?branch=master)](https://travis-ci.org/prometheus/client_golang)
[![Go Report Card](https://goreportcard.com/badge/github.com/prometheus/client_golang)](https://goreportcard.com/report/github.com/prometheus/client_golang)
[![go-doc](https://godoc.org/github.com/prometheus/client_golang?status.svg)](https://godoc.org/github.com/prometheus/client_golang)
This is the [Go](http://golang.org) client library for
[Prometheus](http://prometheus.io). It has two separate parts, one for
instrumenting application code, and one for creating clients that talk to the
Prometheus HTTP API.
__This library requires Go1.7 or later.__
## Important note about releases, versioning, tagging, stability, and your favorite Go dependency management tool
While our goal is to follow [Semantic Versioning](https://semver.org/), this
repository is still pre-1.0.0. To quote the
[Semantic Versioning spec](https://semver.org/#spec-item-4): “Anything may
change at any time. The public API should not be considered stable.” We know
that this is at odds with the widespread use of this library. However, just
declaring something 1.0.0 doesn't make it 1.0.0. Instead, we are working
towards a 1.0.0 release that actually deserves its major version number.
Having said that, we aim for always keeping the tip of master in a workable
state and for only introducing ”mildly” breaking changes up to and including
[v0.9.0](https://github.com/prometheus/client_golang/milestone/1). After that,
a number of ”hard” breaking changes are planned, see the
[v0.10.0 milestone](https://github.com/prometheus/client_golang/milestone/2),
which should get the library much closer to 1.0.0 state.
Dependency management in Go projects is still in flux, and there are many tools
floating around. While [dep](https://golang.github.io/dep/) might develop into
the de-facto standard tool, it is still officially experimental. The roadmap
for this library has been laid out with a lot of sometimes painful experience
in mind. We really cannot adjust it every other month to the needs of the
currently most popular or most promising Go dependency management tool. The
recommended course of action with dependency management tools is the following:
- Do not expect strict post-1.0.0 semver semantics prior to the 1.0.0
release. If your dependency management tool expects strict post-1.0.0 semver
semantics, you have to wait. Sorry.
- If you want absolute certainty, please lock to a specific commit. You can
also lock to tags, but please don't ask for more tagging. This would suggest
some release or stability testing procedure that simply is not in place. As
said above, we are aiming for stability of the tip of master, but if we
tagged every single commit, locking to tags would be the same as locking to
commits.
- If you want to get the newer features and improvements and are willing to
take the minor risk of newly introduced bugs and “mild” breakage, just always
update to the tip of master (which is essentially the original idea of Go
dependency management). We recommend to not use features marked as
_deprecated_ in this case.
- Once [v0.9.0](https://github.com/prometheus/client_golang/milestone/1) is
out, you could lock to v0.9.x to get bugfixes (and perhaps minor new
features) while avoiding the “hard” breakage that will come with post-0.9
features.
## Instrumenting applications
[![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/prometheus)](http://gocover.io/github.com/prometheus/client_golang/prometheus) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus)
The
[`prometheus` directory](https://github.com/prometheus/client_golang/tree/master/prometheus)
contains the instrumentation library. See the
[best practices section](http://prometheus.io/docs/practices/naming/) of the
Prometheus documentation to learn more about instrumenting applications.
The
[`examples` directory](https://github.com/prometheus/client_golang/tree/master/examples)
contains simple examples of instrumented code.
## Client for the Prometheus HTTP API
[![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/api/prometheus/v1)](http://gocover.io/github.com/prometheus/client_golang/api/prometheus/v1) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/api/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/api)
The
[`api/prometheus` directory](https://github.com/prometheus/client_golang/tree/master/api/prometheus)
contains the client for the
[Prometheus HTTP API](http://prometheus.io/docs/querying/api/). It allows you
to write Go applications that query time series data from a Prometheus
server. It is still in alpha stage.
## Where is `model`, `extraction`, and `text`?
The `model` packages has been moved to
[`prometheus/common/model`](https://github.com/prometheus/common/tree/master/model).
The `extraction` and `text` packages are now contained in
[`prometheus/common/expfmt`](https://github.com/prometheus/common/tree/master/expfmt).
## Contributing and community
See the [contributing guidelines](CONTRIBUTING.md) and the
[Community section](http://prometheus.io/community/) of the homepage.

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0.8.0

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
// Package api provides clients for the HTTP APIs.
package api
import (
"context"
"io/ioutil"
"net"
"net/http"
"net/url"
"path"
"strings"
"time"
)
// DefaultRoundTripper is used if no RoundTripper is set in Config.
var DefaultRoundTripper http.RoundTripper = &http.Transport{
Proxy: http.ProxyFromEnvironment,
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
TLSHandshakeTimeout: 10 * time.Second,
}
// Config defines configuration parameters for a new client.
type Config struct {
// The address of the Prometheus to connect to.
Address string
// RoundTripper is used by the Client to drive HTTP requests. If not
// provided, DefaultRoundTripper will be used.
RoundTripper http.RoundTripper
}
func (cfg *Config) roundTripper() http.RoundTripper {
if cfg.RoundTripper == nil {
return DefaultRoundTripper
}
return cfg.RoundTripper
}
// Client is the interface for an API client.
type Client interface {
URL(ep string, args map[string]string) *url.URL
Do(context.Context, *http.Request) (*http.Response, []byte, error)
}
// NewClient returns a new Client.
//
// It is safe to use the returned Client from multiple goroutines.
func NewClient(cfg Config) (Client, error) {
u, err := url.Parse(cfg.Address)
if err != nil {
return nil, err
}
u.Path = strings.TrimRight(u.Path, "/")
return &httpClient{
endpoint: u,
client: http.Client{Transport: cfg.roundTripper()},
}, nil
}
type httpClient struct {
endpoint *url.URL
client http.Client
}
func (c *httpClient) URL(ep string, args map[string]string) *url.URL {
p := path.Join(c.endpoint.Path, ep)
for arg, val := range args {
arg = ":" + arg
p = strings.Replace(p, arg, val, -1)
}
u := *c.endpoint
u.Path = p
return &u
}
func (c *httpClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
if ctx != nil {
req = req.WithContext(ctx)
}
resp, err := c.client.Do(req)
defer func() {
if resp != nil {
resp.Body.Close()
}
}()
if err != nil {
return nil, nil, err
}
var body []byte
done := make(chan struct{})
go func() {
body, err = ioutil.ReadAll(resp.Body)
close(done)
}()
select {
case <-ctx.Done():
err = resp.Body.Close()
<-done
if err == nil {
err = ctx.Err()
}
case <-done:
}
return resp, body, err
}

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
package api
import (
"net/http"
"net/url"
"testing"
)
func TestConfig(t *testing.T) {
c := Config{}
if c.roundTripper() != DefaultRoundTripper {
t.Fatalf("expected default roundtripper for nil RoundTripper field")
}
}
func TestClientURL(t *testing.T) {
tests := []struct {
address string
endpoint string
args map[string]string
expected string
}{
{
address: "http://localhost:9090",
endpoint: "/test",
expected: "http://localhost:9090/test",
},
{
address: "http://localhost",
endpoint: "/test",
expected: "http://localhost/test",
},
{
address: "http://localhost:9090",
endpoint: "test",
expected: "http://localhost:9090/test",
},
{
address: "http://localhost:9090/prefix",
endpoint: "/test",
expected: "http://localhost:9090/prefix/test",
},
{
address: "https://localhost:9090/",
endpoint: "/test/",
expected: "https://localhost:9090/test",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param",
args: map[string]string{
"param": "content",
},
expected: "http://localhost:9090/test/content",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param/more/:param",
args: map[string]string{
"param": "content",
},
expected: "http://localhost:9090/test/content/more/content",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param/more/:foo",
args: map[string]string{
"param": "content",
"foo": "bar",
},
expected: "http://localhost:9090/test/content/more/bar",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param",
args: map[string]string{
"nonexistent": "content",
},
expected: "http://localhost:9090/test/:param",
},
}
for _, test := range tests {
ep, err := url.Parse(test.address)
if err != nil {
t.Fatal(err)
}
hclient := &httpClient{
endpoint: ep,
client: http.Client{Transport: DefaultRoundTripper},
}
u := hclient.URL(test.endpoint, test.args)
if u.String() != test.expected {
t.Errorf("unexpected result: got %s, want %s", u, test.expected)
continue
}
}
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
// Package v1 provides bindings to the Prometheus HTTP API v1:
// http://prometheus.io/docs/querying/api/
package v1
import (
"context"
"encoding/json"
"fmt"
"net/http"
"strconv"
"time"
"github.com/prometheus/client_golang/api"
"github.com/prometheus/common/model"
)
const (
statusAPIError = 422
apiPrefix = "/api/v1"
epAlertManagers = apiPrefix + "/alertmanagers"
epQuery = apiPrefix + "/query"
epQueryRange = apiPrefix + "/query_range"
epLabelValues = apiPrefix + "/label/:name/values"
epSeries = apiPrefix + "/series"
epTargets = apiPrefix + "/targets"
epSnapshot = apiPrefix + "/admin/tsdb/snapshot"
epDeleteSeries = apiPrefix + "/admin/tsdb/delete_series"
epCleanTombstones = apiPrefix + "/admin/tsdb/clean_tombstones"
epConfig = apiPrefix + "/status/config"
epFlags = apiPrefix + "/status/flags"
)
// ErrorType models the different API error types.
type ErrorType string
// HealthStatus models the health status of a scrape target.
type HealthStatus string
const (
// Possible values for ErrorType.
ErrBadData ErrorType = "bad_data"
ErrTimeout = "timeout"
ErrCanceled = "canceled"
ErrExec = "execution"
ErrBadResponse = "bad_response"
// Possible values for HealthStatus.
HealthGood HealthStatus = "up"
HealthUnknown HealthStatus = "unknown"
HealthBad HealthStatus = "down"
)
// Error is an error returned by the API.
type Error struct {
Type ErrorType
Msg string
}
func (e *Error) Error() string {
return fmt.Sprintf("%s: %s", e.Type, e.Msg)
}
// Range represents a sliced time range.
type Range struct {
// The boundaries of the time range.
Start, End time.Time
// The maximum time between two slices within the boundaries.
Step time.Duration
}
// API provides bindings for Prometheus's v1 API.
type API interface {
// AlertManagers returns an overview of the current state of the Prometheus alert manager discovery.
AlertManagers(ctx context.Context) (AlertManagersResult, error)
// CleanTombstones removes the deleted data from disk and cleans up the existing tombstones.
CleanTombstones(ctx context.Context) error
// Config returns the current Prometheus configuration.
Config(ctx context.Context) (ConfigResult, error)
// DeleteSeries deletes data for a selection of series in a time range.
DeleteSeries(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) error
// Flags returns the flag values that Prometheus was launched with.
Flags(ctx context.Context) (FlagsResult, error)
// LabelValues performs a query for the values of the given label.
LabelValues(ctx context.Context, label string) (model.LabelValues, error)
// Query performs a query for the given time.
Query(ctx context.Context, query string, ts time.Time) (model.Value, error)
// QueryRange performs a query for the given range.
QueryRange(ctx context.Context, query string, r Range) (model.Value, error)
// Series finds series by label matchers.
Series(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) ([]model.LabelSet, error)
// Snapshot creates a snapshot of all current data into snapshots/<datetime>-<rand>
// under the TSDB's data directory and returns the directory as response.
Snapshot(ctx context.Context, skipHead bool) (SnapshotResult, error)
// Targets returns an overview of the current state of the Prometheus target discovery.
Targets(ctx context.Context) (TargetsResult, error)
}
// AlertManagersResult contains the result from querying the alertmanagers endpoint.
type AlertManagersResult struct {
Active []AlertManager `json:"activeAlertManagers"`
Dropped []AlertManager `json:"droppedAlertManagers"`
}
// AlertManager models a configured Alert Manager.
type AlertManager struct {
URL string `json:"url"`
}
// ConfigResult contains the result from querying the config endpoint.
type ConfigResult struct {
YAML string `json:"yaml"`
}
// FlagsResult contains the result from querying the flag endpoint.
type FlagsResult map[string]string
// SnapshotResult contains the result from querying the snapshot endpoint.
type SnapshotResult struct {
Name string `json:"name"`
}
// TargetsResult contains the result from querying the targets endpoint.
type TargetsResult struct {
Active []ActiveTarget `json:"activeTargets"`
Dropped []DroppedTarget `json:"droppedTargets"`
}
// ActiveTarget models an active Prometheus scrape target.
type ActiveTarget struct {
DiscoveredLabels model.LabelSet `json:"discoveredLabels"`
Labels model.LabelSet `json:"labels"`
ScrapeURL string `json:"scrapeUrl"`
LastError string `json:"lastError"`
LastScrape time.Time `json:"lastScrape"`
Health HealthStatus `json:"health"`
}
// DroppedTarget models a dropped Prometheus scrape target.
type DroppedTarget struct {
DiscoveredLabels model.LabelSet `json:"discoveredLabels"`
}
// queryResult contains result data for a query.
type queryResult struct {
Type model.ValueType `json:"resultType"`
Result interface{} `json:"result"`
// The decoded value.
v model.Value
}
func (qr *queryResult) UnmarshalJSON(b []byte) error {
v := struct {
Type model.ValueType `json:"resultType"`
Result json.RawMessage `json:"result"`
}{}
err := json.Unmarshal(b, &v)
if err != nil {
return err
}
switch v.Type {
case model.ValScalar:
var sv model.Scalar
err = json.Unmarshal(v.Result, &sv)
qr.v = &sv
case model.ValVector:
var vv model.Vector
err = json.Unmarshal(v.Result, &vv)
qr.v = vv
case model.ValMatrix:
var mv model.Matrix
err = json.Unmarshal(v.Result, &mv)
qr.v = mv
default:
err = fmt.Errorf("unexpected value type %q", v.Type)
}
return err
}
// NewAPI returns a new API for the client.
//
// It is safe to use the returned API from multiple goroutines.
func NewAPI(c api.Client) API {
return &httpAPI{client: apiClient{c}}
}
type httpAPI struct {
client api.Client
}
func (h *httpAPI) AlertManagers(ctx context.Context) (AlertManagersResult, error) {
u := h.client.URL(epAlertManagers, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return AlertManagersResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return AlertManagersResult{}, err
}
var res AlertManagersResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) CleanTombstones(ctx context.Context) error {
u := h.client.URL(epCleanTombstones, nil)
req, err := http.NewRequest(http.MethodPost, u.String(), nil)
if err != nil {
return err
}
_, _, err = h.client.Do(ctx, req)
return err
}
func (h *httpAPI) Config(ctx context.Context) (ConfigResult, error) {
u := h.client.URL(epConfig, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return ConfigResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return ConfigResult{}, err
}
var res ConfigResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) DeleteSeries(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) error {
u := h.client.URL(epDeleteSeries, nil)
q := u.Query()
for _, m := range matches {
q.Add("match[]", m)
}
q.Set("start", startTime.Format(time.RFC3339Nano))
q.Set("end", endTime.Format(time.RFC3339Nano))
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodPost, u.String(), nil)
if err != nil {
return err
}
_, _, err = h.client.Do(ctx, req)
return err
}
func (h *httpAPI) Flags(ctx context.Context) (FlagsResult, error) {
u := h.client.URL(epFlags, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return FlagsResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return FlagsResult{}, err
}
var res FlagsResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) LabelValues(ctx context.Context, label string) (model.LabelValues, error) {
u := h.client.URL(epLabelValues, map[string]string{"name": label})
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var labelValues model.LabelValues
err = json.Unmarshal(body, &labelValues)
return labelValues, err
}
func (h *httpAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, error) {
u := h.client.URL(epQuery, nil)
q := u.Query()
q.Set("query", query)
if !ts.IsZero() {
q.Set("time", ts.Format(time.RFC3339Nano))
}
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var qres queryResult
err = json.Unmarshal(body, &qres)
return model.Value(qres.v), err
}
func (h *httpAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, error) {
u := h.client.URL(epQueryRange, nil)
q := u.Query()
var (
start = r.Start.Format(time.RFC3339Nano)
end = r.End.Format(time.RFC3339Nano)
step = strconv.FormatFloat(r.Step.Seconds(), 'f', 3, 64)
)
q.Set("query", query)
q.Set("start", start)
q.Set("end", end)
q.Set("step", step)
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var qres queryResult
err = json.Unmarshal(body, &qres)
return model.Value(qres.v), err
}
func (h *httpAPI) Series(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) ([]model.LabelSet, error) {
u := h.client.URL(epSeries, nil)
q := u.Query()
for _, m := range matches {
q.Add("match[]", m)
}
q.Set("start", startTime.Format(time.RFC3339Nano))
q.Set("end", endTime.Format(time.RFC3339Nano))
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var mset []model.LabelSet
err = json.Unmarshal(body, &mset)
return mset, err
}
func (h *httpAPI) Snapshot(ctx context.Context, skipHead bool) (SnapshotResult, error) {
u := h.client.URL(epSnapshot, nil)
q := u.Query()
q.Set("skip_head", strconv.FormatBool(skipHead))
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodPost, u.String(), nil)
if err != nil {
return SnapshotResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return SnapshotResult{}, err
}
var res SnapshotResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) Targets(ctx context.Context) (TargetsResult, error) {
u := h.client.URL(epTargets, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return TargetsResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return TargetsResult{}, err
}
var res TargetsResult
err = json.Unmarshal(body, &res)
return res, err
}
// apiClient wraps a regular client and processes successful API responses.
// Successful also includes responses that errored at the API level.
type apiClient struct {
api.Client
}
type apiResponse struct {
Status string `json:"status"`
Data json.RawMessage `json:"data"`
ErrorType ErrorType `json:"errorType"`
Error string `json:"error"`
}
func (c apiClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
resp, body, err := c.Client.Do(ctx, req)
if err != nil {
return resp, body, err
}
code := resp.StatusCode
if code/100 != 2 && code != statusAPIError {
return resp, body, &Error{
Type: ErrBadResponse,
Msg: fmt.Sprintf("bad response code %d", resp.StatusCode),
}
}
var result apiResponse
if err = json.Unmarshal(body, &result); err != nil {
return resp, body, &Error{
Type: ErrBadResponse,
Msg: err.Error(),
}
}
if (code == statusAPIError) != (result.Status == "error") {
err = &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
}
}
if code == statusAPIError && result.Status == "error" {
err = &Error{
Type: result.ErrorType,
Msg: result.Error,
}
}
return resp, []byte(result.Data), err
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
package v1
import (
"context"
"encoding/json"
"fmt"
"net/http"
"net/url"
"reflect"
"strings"
"testing"
"time"
"github.com/prometheus/common/model"
)
type apiTest struct {
do func() (interface{}, error)
inErr error
inRes interface{}
reqPath string
reqParam url.Values
reqMethod string
res interface{}
err error
}
type apiTestClient struct {
*testing.T
curTest apiTest
}
func (c *apiTestClient) URL(ep string, args map[string]string) *url.URL {
path := ep
for k, v := range args {
path = strings.Replace(path, ":"+k, v, -1)
}
u := &url.URL{
Host: "test:9090",
Path: path,
}
return u
}
func (c *apiTestClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
test := c.curTest
if req.URL.Path != test.reqPath {
c.Errorf("unexpected request path: want %s, got %s", test.reqPath, req.URL.Path)
}
if req.Method != test.reqMethod {
c.Errorf("unexpected request method: want %s, got %s", test.reqMethod, req.Method)
}
b, err := json.Marshal(test.inRes)
if err != nil {
c.Fatal(err)
}
resp := &http.Response{}
if test.inErr != nil {
resp.StatusCode = statusAPIError
} else {
resp.StatusCode = http.StatusOK
}
return resp, b, test.inErr
}
func TestAPIs(t *testing.T) {
testTime := time.Now()
client := &apiTestClient{T: t}
promAPI := &httpAPI{
client: client,
}
doAlertManagers := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.AlertManagers(context.Background())
}
}
doCleanTombstones := func() func() (interface{}, error) {
return func() (interface{}, error) {
return nil, promAPI.CleanTombstones(context.Background())
}
}
doConfig := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Config(context.Background())
}
}
doDeleteSeries := func(matcher string, startTime time.Time, endTime time.Time) func() (interface{}, error) {
return func() (interface{}, error) {
return nil, promAPI.DeleteSeries(context.Background(), []string{matcher}, startTime, endTime)
}
}
doFlags := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Flags(context.Background())
}
}
doLabelValues := func(label string) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.LabelValues(context.Background(), label)
}
}
doQuery := func(q string, ts time.Time) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Query(context.Background(), q, ts)
}
}
doQueryRange := func(q string, rng Range) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.QueryRange(context.Background(), q, rng)
}
}
doSeries := func(matcher string, startTime time.Time, endTime time.Time) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Series(context.Background(), []string{matcher}, startTime, endTime)
}
}
doSnapshot := func(skipHead bool) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Snapshot(context.Background(), skipHead)
}
}
doTargets := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Targets(context.Background())
}
}
queryTests := []apiTest{
{
do: doQuery("2", testTime),
inRes: &queryResult{
Type: model.ValScalar,
Result: &model.Scalar{
Value: 2,
Timestamp: model.TimeFromUnix(testTime.Unix()),
},
},
reqMethod: "GET",
reqPath: "/api/v1/query",
reqParam: url.Values{
"query": []string{"2"},
"time": []string{testTime.Format(time.RFC3339Nano)},
},
res: &model.Scalar{
Value: 2,
Timestamp: model.TimeFromUnix(testTime.Unix()),
},
},
{
do: doQuery("2", testTime),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/query",
reqParam: url.Values{
"query": []string{"2"},
"time": []string{testTime.Format(time.RFC3339Nano)},
},
err: fmt.Errorf("some error"),
},
{
do: doQueryRange("2", Range{
Start: testTime.Add(-time.Minute),
End: testTime,
Step: time.Minute,
}),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/query_range",
reqParam: url.Values{
"query": []string{"2"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
"step": []string{time.Minute.String()},
},
err: fmt.Errorf("some error"),
},
{
do: doLabelValues("mylabel"),
inRes: []string{"val1", "val2"},
reqMethod: "GET",
reqPath: "/api/v1/label/mylabel/values",
res: model.LabelValues{"val1", "val2"},
},
{
do: doLabelValues("mylabel"),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/label/mylabel/values",
err: fmt.Errorf("some error"),
},
{
do: doSeries("up", testTime.Add(-time.Minute), testTime),
inRes: []map[string]string{
{
"__name__": "up",
"job": "prometheus",
"instance": "localhost:9090"},
},
reqMethod: "GET",
reqPath: "/api/v1/series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
res: []model.LabelSet{
model.LabelSet{
"__name__": "up",
"job": "prometheus",
"instance": "localhost:9090",
},
},
},
{
do: doSeries("up", testTime.Add(-time.Minute), testTime),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
err: fmt.Errorf("some error"),
},
{
do: doSnapshot(true),
inRes: map[string]string{
"name": "20171210T211224Z-2be650b6d019eb54",
},
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/snapshot",
reqParam: url.Values{
"skip_head": []string{"true"},
},
res: SnapshotResult{
Name: "20171210T211224Z-2be650b6d019eb54",
},
},
{
do: doSnapshot(true),
inErr: fmt.Errorf("some error"),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/snapshot",
err: fmt.Errorf("some error"),
},
{
do: doCleanTombstones(),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/clean_tombstones",
},
{
do: doCleanTombstones(),
inErr: fmt.Errorf("some error"),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/clean_tombstones",
err: fmt.Errorf("some error"),
},
{
do: doDeleteSeries("up", testTime.Add(-time.Minute), testTime),
inRes: []map[string]string{
{
"__name__": "up",
"job": "prometheus",
"instance": "localhost:9090"},
},
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/delete_series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
},
{
do: doDeleteSeries("up", testTime.Add(-time.Minute), testTime),
inErr: fmt.Errorf("some error"),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/delete_series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
err: fmt.Errorf("some error"),
},
{
do: doConfig(),
reqMethod: "GET",
reqPath: "/api/v1/status/config",
inRes: map[string]string{
"yaml": "<content of the loaded config file in YAML>",
},
res: ConfigResult{
YAML: "<content of the loaded config file in YAML>",
},
},
{
do: doConfig(),
reqMethod: "GET",
reqPath: "/api/v1/status/config",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
{
do: doFlags(),
reqMethod: "GET",
reqPath: "/api/v1/status/flags",
inRes: map[string]string{
"alertmanager.notification-queue-capacity": "10000",
"alertmanager.timeout": "10s",
"log.level": "info",
"query.lookback-delta": "5m",
"query.max-concurrency": "20",
},
res: FlagsResult{
"alertmanager.notification-queue-capacity": "10000",
"alertmanager.timeout": "10s",
"log.level": "info",
"query.lookback-delta": "5m",
"query.max-concurrency": "20",
},
},
{
do: doFlags(),
reqMethod: "GET",
reqPath: "/api/v1/status/flags",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
{
do: doAlertManagers(),
reqMethod: "GET",
reqPath: "/api/v1/alertmanagers",
inRes: map[string]interface{}{
"activeAlertManagers": []map[string]string{
{
"url": "http://127.0.0.1:9091/api/v1/alerts",
},
},
"droppedAlertManagers": []map[string]string{
{
"url": "http://127.0.0.1:9092/api/v1/alerts",
},
},
},
res: AlertManagersResult{
Active: []AlertManager{
{
URL: "http://127.0.0.1:9091/api/v1/alerts",
},
},
Dropped: []AlertManager{
{
URL: "http://127.0.0.1:9092/api/v1/alerts",
},
},
},
},
{
do: doAlertManagers(),
reqMethod: "GET",
reqPath: "/api/v1/alertmanagers",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
{
do: doTargets(),
reqMethod: "GET",
reqPath: "/api/v1/targets",
inRes: map[string]interface{}{
"activeTargets": []map[string]interface{}{
{
"discoveredLabels": map[string]string{
"__address__": "127.0.0.1:9090",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "prometheus",
},
"labels": map[string]string{
"instance": "127.0.0.1:9090",
"job": "prometheus",
},
"scrapeUrl": "http://127.0.0.1:9090",
"lastError": "error while scraping target",
"lastScrape": testTime.UTC().Format(time.RFC3339Nano),
"health": "up",
},
},
"droppedTargets": []map[string]interface{}{
{
"discoveredLabels": map[string]string{
"__address__": "127.0.0.1:9100",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "node",
},
},
},
},
res: TargetsResult{
Active: []ActiveTarget{
{
DiscoveredLabels: model.LabelSet{
"__address__": "127.0.0.1:9090",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "prometheus",
},
Labels: model.LabelSet{
"instance": "127.0.0.1:9090",
"job": "prometheus",
},
ScrapeURL: "http://127.0.0.1:9090",
LastError: "error while scraping target",
LastScrape: testTime.UTC(),
Health: HealthGood,
},
},
Dropped: []DroppedTarget{
{
DiscoveredLabels: model.LabelSet{
"__address__": "127.0.0.1:9100",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "node",
},
},
},
},
},
{
do: doTargets(),
reqMethod: "GET",
reqPath: "/api/v1/targets",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
}
var tests []apiTest
tests = append(tests, queryTests...)
for _, test := range tests {
client.curTest = test
res, err := test.do()
if test.err != nil {
if err == nil {
t.Errorf("expected error %q but got none", test.err)
continue
}
if err.Error() != test.err.Error() {
t.Errorf("unexpected error: want %s, got %s", test.err, err)
}
continue
}
if err != nil {
t.Errorf("unexpected error: %s", err)
continue
}
if !reflect.DeepEqual(res, test.res) {
t.Errorf("unexpected result: want %v, got %v", test.res, res)
}
}
}
type testClient struct {
*testing.T
ch chan apiClientTest
req *http.Request
}
type apiClientTest struct {
code int
response interface{}
expected string
err *Error
}
func (c *testClient) URL(ep string, args map[string]string) *url.URL {
return nil
}
func (c *testClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
if ctx == nil {
c.Fatalf("context was not passed down")
}
if req != c.req {
c.Fatalf("request was not passed down")
}
test := <-c.ch
var b []byte
var err error
switch v := test.response.(type) {
case string:
b = []byte(v)
default:
b, err = json.Marshal(v)
if err != nil {
c.Fatal(err)
}
}
resp := &http.Response{
StatusCode: test.code,
}
return resp, b, nil
}
func TestAPIClientDo(t *testing.T) {
tests := []apiClientTest{
{
response: &apiResponse{
Status: "error",
Data: json.RawMessage(`null`),
ErrorType: ErrBadData,
Error: "failed",
},
err: &Error{
Type: ErrBadData,
Msg: "failed",
},
code: statusAPIError,
expected: `null`,
},
{
response: &apiResponse{
Status: "error",
Data: json.RawMessage(`"test"`),
ErrorType: ErrTimeout,
Error: "timed out",
},
err: &Error{
Type: ErrTimeout,
Msg: "timed out",
},
code: statusAPIError,
expected: `test`,
},
{
response: "bad json",
err: &Error{
Type: ErrBadResponse,
Msg: "bad response code 400",
},
code: http.StatusBadRequest,
},
{
response: "bad json",
err: &Error{
Type: ErrBadResponse,
Msg: "invalid character 'b' looking for beginning of value",
},
code: statusAPIError,
},
{
response: &apiResponse{
Status: "success",
Data: json.RawMessage(`"test"`),
},
err: &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
},
code: statusAPIError,
},
{
response: &apiResponse{
Status: "success",
Data: json.RawMessage(`"test"`),
ErrorType: ErrTimeout,
Error: "timed out",
},
err: &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
},
code: statusAPIError,
},
{
response: &apiResponse{
Status: "error",
Data: json.RawMessage(`"test"`),
ErrorType: ErrTimeout,
Error: "timed out",
},
err: &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
},
code: http.StatusOK,
},
}
tc := &testClient{
T: t,
ch: make(chan apiClientTest, 1),
req: &http.Request{},
}
client := &apiClient{tc}
for _, test := range tests {
tc.ch <- test
_, body, err := client.Do(context.Background(), tc.req)
if test.err != nil {
if err == nil {
t.Errorf("expected error %q but got none", test.err)
continue
}
if test.err.Error() != err.Error() {
t.Errorf("unexpected error: want %q, got %q", test.err, err)
}
continue
}
if err != nil {
t.Errorf("unexpeceted error %s", err)
continue
}
want, got := test.expected, string(body)
if want != got {
t.Errorf("unexpected body: want %q, got %q", want, got)
}
}
}

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# This Dockerfile builds an image for a client_golang example.
#
# Use as (from the root for the client_golang repository):
# docker build -f examples/$name/Dockerfile -t prometheus/golang-example-$name .
# Builder image, where we build the example.
FROM golang:1.9.0 AS builder
WORKDIR /go/src/github.com/prometheus/client_golang
COPY . .
WORKDIR /go/src/github.com/prometheus/client_golang/prometheus
RUN go get -d
WORKDIR /go/src/github.com/prometheus/client_golang/examples/random
RUN CGO_ENABLED=0 GOOS=linux go build -a -tags netgo -ldflags '-w'
# Final image.
FROM scratch
LABEL maintainer "The Prometheus Authors <prometheus-developers@googlegroups.com>"
COPY --from=builder /go/src/github.com/prometheus/client_golang/examples/random .
EXPOSE 8080
ENTRYPOINT ["/random"]

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// A simple example exposing fictional RPC latencies with different types of
// random distributions (uniform, normal, and exponential) as Prometheus
// metrics.
package main
import (
"flag"
"log"
"math"
"math/rand"
"net/http"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
var (
addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
uniformDomain = flag.Float64("uniform.domain", 0.0002, "The domain for the uniform distribution.")
normDomain = flag.Float64("normal.domain", 0.0002, "The domain for the normal distribution.")
normMean = flag.Float64("normal.mean", 0.00001, "The mean for the normal distribution.")
oscillationPeriod = flag.Duration("oscillation-period", 10*time.Minute, "The duration of the rate oscillation period.")
)
var (
// Create a summary to track fictional interservice RPC latencies for three
// distinct services with different latency distributions. These services are
// differentiated via a "service" label.
rpcDurations = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "rpc_durations_seconds",
Help: "RPC latency distributions.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"service"},
)
// The same as above, but now as a histogram, and only for the normal
// distribution. The buckets are targeted to the parameters of the
// normal distribution, with 20 buckets centered on the mean, each
// half-sigma wide.
rpcDurationsHistogram = prometheus.NewHistogram(prometheus.HistogramOpts{
Name: "rpc_durations_histogram_seconds",
Help: "RPC latency distributions.",
Buckets: prometheus.LinearBuckets(*normMean-5**normDomain, .5**normDomain, 20),
})
)
func init() {
// Register the summary and the histogram with Prometheus's default registry.
prometheus.MustRegister(rpcDurations)
prometheus.MustRegister(rpcDurationsHistogram)
}
func main() {
flag.Parse()
start := time.Now()
oscillationFactor := func() float64 {
return 2 + math.Sin(math.Sin(2*math.Pi*float64(time.Since(start))/float64(*oscillationPeriod)))
}
// Periodically record some sample latencies for the three services.
go func() {
for {
v := rand.Float64() * *uniformDomain
rpcDurations.WithLabelValues("uniform").Observe(v)
time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond)
}
}()
go func() {
for {
v := (rand.NormFloat64() * *normDomain) + *normMean
rpcDurations.WithLabelValues("normal").Observe(v)
rpcDurationsHistogram.Observe(v)
time.Sleep(time.Duration(75*oscillationFactor()) * time.Millisecond)
}
}()
go func() {
for {
v := rand.ExpFloat64() / 1e6
rpcDurations.WithLabelValues("exponential").Observe(v)
time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond)
}
}()
// Expose the registered metrics via HTTP.
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}

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# This Dockerfile builds an image for a client_golang example.
#
# Use as (from the root for the client_golang repository):
# docker build -f examples/$name/Dockerfile -t prometheus/golang-example-$name .
# Builder image, where we build the example.
FROM golang:1.9.0 AS builder
WORKDIR /go/src/github.com/prometheus/client_golang
COPY . .
WORKDIR /go/src/github.com/prometheus/client_golang/prometheus
RUN go get -d
WORKDIR /go/src/github.com/prometheus/client_golang/examples/simple
RUN CGO_ENABLED=0 GOOS=linux go build -a -tags netgo -ldflags '-w'
# Final image.
FROM scratch
LABEL maintainer "The Prometheus Authors <prometheus-developers@googlegroups.com>"
COPY --from=builder /go/src/github.com/prometheus/client_golang/examples/simple .
EXPOSE 8080
ENTRYPOINT ["/simple"]

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@ -0,0 +1,31 @@
// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// A minimal example of how to include Prometheus instrumentation.
package main
import (
"flag"
"log"
"net/http"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
var addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
func main() {
flag.Parse()
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}

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@ -0,0 +1 @@
See [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus).

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"sync"
"testing"
)
func BenchmarkCounterWithLabelValues(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Inc()
}
}
func BenchmarkCounterWithLabelValuesConcurrent(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
wg := sync.WaitGroup{}
for i := 0; i < 10; i++ {
wg.Add(1)
go func() {
for j := 0; j < b.N/10; j++ {
m.WithLabelValues("eins", "zwei", "drei").Inc()
}
wg.Done()
}()
}
wg.Wait()
}
func BenchmarkCounterWithMappedLabels(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.With(Labels{"two": "zwei", "one": "eins", "three": "drei"}).Inc()
}
}
func BenchmarkCounterWithPreparedMappedLabels(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
labels := Labels{"two": "zwei", "one": "eins", "three": "drei"}
for i := 0; i < b.N; i++ {
m.With(labels).Inc()
}
}
func BenchmarkCounterNoLabels(b *testing.B) {
m := NewCounter(CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
})
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Inc()
}
}
func BenchmarkGaugeWithLabelValues(b *testing.B) {
m := NewGaugeVec(
GaugeOpts{
Name: "benchmark_gauge",
Help: "A gauge to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Set(3.1415)
}
}
func BenchmarkGaugeNoLabels(b *testing.B) {
m := NewGauge(GaugeOpts{
Name: "benchmark_gauge",
Help: "A gauge to benchmark it.",
})
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Set(3.1415)
}
}
func BenchmarkSummaryWithLabelValues(b *testing.B) {
m := NewSummaryVec(
SummaryOpts{
Name: "benchmark_summary",
Help: "A summary to benchmark it.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Observe(3.1415)
}
}
func BenchmarkSummaryNoLabels(b *testing.B) {
m := NewSummary(SummaryOpts{
Name: "benchmark_summary",
Help: "A summary to benchmark it.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Observe(3.1415)
}
}
func BenchmarkHistogramWithLabelValues(b *testing.B) {
m := NewHistogramVec(
HistogramOpts{
Name: "benchmark_histogram",
Help: "A histogram to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Observe(3.1415)
}
}
func BenchmarkHistogramNoLabels(b *testing.B) {
m := NewHistogram(HistogramOpts{
Name: "benchmark_histogram",
Help: "A histogram to benchmark it.",
},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Observe(3.1415)
}
}
func BenchmarkParallelCounter(b *testing.B) {
c := NewCounter(CounterOpts{
Name: "benchmark_counter",
Help: "A Counter to benchmark it.",
})
b.ReportAllocs()
b.ResetTimer()
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
c.Inc()
}
})
}

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@ -0,0 +1,75 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Collector is the interface implemented by anything that can be used by
// Prometheus to collect metrics. A Collector has to be registered for
// collection. See Registerer.Register.
//
// The stock metrics provided by this package (Gauge, Counter, Summary,
// Histogram, Untyped) are also Collectors (which only ever collect one metric,
// namely itself). An implementer of Collector may, however, collect multiple
// metrics in a coordinated fashion and/or create metrics on the fly. Examples
// for collectors already implemented in this library are the metric vectors
// (i.e. collection of multiple instances of the same Metric but with different
// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
type Collector interface {
// Describe sends the super-set of all possible descriptors of metrics
// collected by this Collector to the provided channel and returns once
// the last descriptor has been sent. The sent descriptors fulfill the
// consistency and uniqueness requirements described in the Desc
// documentation. (It is valid if one and the same Collector sends
// duplicate descriptors. Those duplicates are simply ignored. However,
// two different Collectors must not send duplicate descriptors.) This
// method idempotently sends the same descriptors throughout the
// lifetime of the Collector. If a Collector encounters an error while
// executing this method, it must send an invalid descriptor (created
// with NewInvalidDesc) to signal the error to the registry.
Describe(chan<- *Desc)
// Collect is called by the Prometheus registry when collecting
// metrics. The implementation sends each collected metric via the
// provided channel and returns once the last metric has been sent. The
// descriptor of each sent metric is one of those returned by
// Describe. Returned metrics that share the same descriptor must differ
// in their variable label values. This method may be called
// concurrently and must therefore be implemented in a concurrency safe
// way. Blocking occurs at the expense of total performance of rendering
// all registered metrics. Ideally, Collector implementations support
// concurrent readers.
Collect(chan<- Metric)
}
// selfCollector implements Collector for a single Metric so that the Metric
// collects itself. Add it as an anonymous field to a struct that implements
// Metric, and call init with the Metric itself as an argument.
type selfCollector struct {
self Metric
}
// init provides the selfCollector with a reference to the metric it is supposed
// to collect. It is usually called within the factory function to create a
// metric. See example.
func (c *selfCollector) init(self Metric) {
c.self = self
}
// Describe implements Collector.
func (c *selfCollector) Describe(ch chan<- *Desc) {
ch <- c.self.Desc()
}
// Collect implements Collector.
func (c *selfCollector) Collect(ch chan<- Metric) {
ch <- c.self
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"math"
"sync/atomic"
dto "github.com/prometheus/client_model/go"
)
// Counter is a Metric that represents a single numerical value that only ever
// goes up. That implies that it cannot be used to count items whose number can
// also go down, e.g. the number of currently running goroutines. Those
// "counters" are represented by Gauges.
//
// A Counter is typically used to count requests served, tasks completed, errors
// occurred, etc.
//
// To create Counter instances, use NewCounter.
type Counter interface {
Metric
Collector
// Inc increments the counter by 1. Use Add to increment it by arbitrary
// non-negative values.
Inc()
// Add adds the given value to the counter. It panics if the value is <
// 0.
Add(float64)
}
// CounterOpts is an alias for Opts. See there for doc comments.
type CounterOpts Opts
// NewCounter creates a new Counter based on the provided CounterOpts.
//
// The returned implementation tracks the counter value in two separate
// variables, a float64 and a uint64. The latter is used to track calls of the
// Inc method and calls of the Add method with a value that can be represented
// as a uint64. This allows atomic increments of the counter with optimal
// performance. (It is common to have an Inc call in very hot execution paths.)
// Both internal tracking values are added up in the Write method. This has to
// be taken into account when it comes to precision and overflow behavior.
func NewCounter(opts CounterOpts) Counter {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
)
result := &counter{desc: desc, labelPairs: desc.constLabelPairs}
result.init(result) // Init self-collection.
return result
}
type counter struct {
// valBits contains the bits of the represented float64 value, while
// valInt stores values that are exact integers. Both have to go first
// in the struct to guarantee alignment for atomic operations.
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
valBits uint64
valInt uint64
selfCollector
desc *Desc
labelPairs []*dto.LabelPair
}
func (c *counter) Desc() *Desc {
return c.desc
}
func (c *counter) Add(v float64) {
if v < 0 {
panic(errors.New("counter cannot decrease in value"))
}
ival := uint64(v)
if float64(ival) == v {
atomic.AddUint64(&c.valInt, ival)
return
}
for {
oldBits := atomic.LoadUint64(&c.valBits)
newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
return
}
}
}
func (c *counter) Inc() {
atomic.AddUint64(&c.valInt, 1)
}
func (c *counter) Write(out *dto.Metric) error {
fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
ival := atomic.LoadUint64(&c.valInt)
val := fval + float64(ival)
return populateMetric(CounterValue, val, c.labelPairs, out)
}
// CounterVec is a Collector that bundles a set of Counters that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. number of HTTP requests, partitioned by response code and
// method). Create instances with NewCounterVec.
type CounterVec struct {
*metricVec
}
// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
// partitioned by the given label names.
func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &CounterVec{
metricVec: newMetricVec(desc, func(lvs ...string) Metric {
if len(lvs) != len(desc.variableLabels) {
panic(errInconsistentCardinality)
}
result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
result.init(result) // Init self-collection.
return result
}),
}
}
// GetMetricWithLabelValues returns the Counter for the given slice of label
// values (same order as the VariableLabels in Desc). If that combination of
// label values is accessed for the first time, a new Counter is created.
//
// It is possible to call this method without using the returned Counter to only
// create the new Counter but leave it at its starting value 0. See also the
// SummaryVec example.
//
// Keeping the Counter for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Counter from the CounterVec. In that case,
// the Counter will still exist, but it will not be exported anymore, even if a
// Counter with the same label values is created later.
//
// An error is returned if the number of label values is not the same as the
// number of VariableLabels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the GaugeVec example.
func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// GetMetricWith returns the Counter for the given Labels map (the label names
// must match those of the VariableLabels in Desc). If that label map is
// accessed for the first time, a new Counter is created. Implications of
// creating a Counter without using it and keeping the Counter for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
// myVec.WithLabelValues("404", "GET").Add(42)
func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
c, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return c
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
func (v *CounterVec) With(labels Labels) Counter {
c, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return c
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the CounterVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &CounterVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
// CounterFunc is a Counter whose value is determined at collect time by calling a
// provided function.
//
// To create CounterFunc instances, use NewCounterFunc.
type CounterFunc interface {
Metric
Collector
}
// NewCounterFunc creates a new CounterFunc based on the provided
// CounterOpts. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where a CounterFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe. The function should also honor
// the contract for a Counter (values only go up, not down), but compliance will
// not be checked.
func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), CounterValue, function)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"math"
"testing"
dto "github.com/prometheus/client_model/go"
)
func TestCounterAdd(t *testing.T) {
counter := NewCounter(CounterOpts{
Name: "test",
Help: "test help",
ConstLabels: Labels{"a": "1", "b": "2"},
}).(*counter)
counter.Inc()
if expected, got := 0.0, math.Float64frombits(counter.valBits); expected != got {
t.Errorf("Expected %f, got %f.", expected, got)
}
if expected, got := uint64(1), counter.valInt; expected != got {
t.Errorf("Expected %d, got %d.", expected, got)
}
counter.Add(42)
if expected, got := 0.0, math.Float64frombits(counter.valBits); expected != got {
t.Errorf("Expected %f, got %f.", expected, got)
}
if expected, got := uint64(43), counter.valInt; expected != got {
t.Errorf("Expected %d, got %d.", expected, got)
}
counter.Add(24.42)
if expected, got := 24.42, math.Float64frombits(counter.valBits); expected != got {
t.Errorf("Expected %f, got %f.", expected, got)
}
if expected, got := uint64(43), counter.valInt; expected != got {
t.Errorf("Expected %d, got %d.", expected, got)
}
if expected, got := "counter cannot decrease in value", decreaseCounter(counter).Error(); expected != got {
t.Errorf("Expected error %q, got %q.", expected, got)
}
m := &dto.Metric{}
counter.Write(m)
if expected, got := `label:<name:"a" value:"1" > label:<name:"b" value:"2" > counter:<value:67.42 > `, m.String(); expected != got {
t.Errorf("expected %q, got %q", expected, got)
}
}
func decreaseCounter(c *counter) (err error) {
defer func() {
if e := recover(); e != nil {
err = e.(error)
}
}()
c.Add(-1)
return nil
}
func TestCounterVecGetMetricWithInvalidLabelValues(t *testing.T) {
testCases := []struct {
desc string
labels Labels
}{
{
desc: "non utf8 label value",
labels: Labels{"a": "\xFF"},
},
{
desc: "not enough label values",
labels: Labels{},
},
{
desc: "too many label values",
labels: Labels{"a": "1", "b": "2"},
},
}
for _, test := range testCases {
counterVec := NewCounterVec(CounterOpts{
Name: "test",
}, []string{"a"})
labelValues := make([]string, len(test.labels))
for _, val := range test.labels {
labelValues = append(labelValues, val)
}
expectPanic(t, func() {
counterVec.WithLabelValues(labelValues...)
}, fmt.Sprintf("WithLabelValues: expected panic because: %s", test.desc))
expectPanic(t, func() {
counterVec.With(test.labels)
}, fmt.Sprintf("WithLabelValues: expected panic because: %s", test.desc))
if _, err := counterVec.GetMetricWithLabelValues(labelValues...); err == nil {
t.Errorf("GetMetricWithLabelValues: expected error because: %s", test.desc)
}
if _, err := counterVec.GetMetricWith(test.labels); err == nil {
t.Errorf("GetMetricWith: expected error because: %s", test.desc)
}
}
}
func expectPanic(t *testing.T, op func(), errorMsg string) {
defer func() {
if err := recover(); err == nil {
t.Error(errorMsg)
}
}()
op()
}
func TestCounterAddInf(t *testing.T) {
counter := NewCounter(CounterOpts{
Name: "test",
Help: "test help",
}).(*counter)
counter.Inc()
if expected, got := 0.0, math.Float64frombits(counter.valBits); expected != got {
t.Errorf("Expected %f, got %f.", expected, got)
}
if expected, got := uint64(1), counter.valInt; expected != got {
t.Errorf("Expected %d, got %d.", expected, got)
}
counter.Add(math.Inf(1))
if expected, got := math.Inf(1), math.Float64frombits(counter.valBits); expected != got {
t.Errorf("valBits expected %f, got %f.", expected, got)
}
if expected, got := uint64(1), counter.valInt; expected != got {
t.Errorf("valInts expected %d, got %d.", expected, got)
}
counter.Inc()
if expected, got := math.Inf(1), math.Float64frombits(counter.valBits); expected != got {
t.Errorf("Expected %f, got %f.", expected, got)
}
if expected, got := uint64(2), counter.valInt; expected != got {
t.Errorf("Expected %d, got %d.", expected, got)
}
m := &dto.Metric{}
counter.Write(m)
if expected, got := `counter:<value:inf > `, m.String(); expected != got {
t.Errorf("expected %q, got %q", expected, got)
}
}
func TestCounterAddLarge(t *testing.T) {
counter := NewCounter(CounterOpts{
Name: "test",
Help: "test help",
}).(*counter)
// large overflows the underlying type and should therefore be stored in valBits.
large := float64(math.MaxUint64 + 1)
counter.Add(large)
if expected, got := large, math.Float64frombits(counter.valBits); expected != got {
t.Errorf("valBits expected %f, got %f.", expected, got)
}
if expected, got := uint64(0), counter.valInt; expected != got {
t.Errorf("valInts expected %d, got %d.", expected, got)
}
m := &dto.Metric{}
counter.Write(m)
if expected, got := fmt.Sprintf("counter:<value:%0.16e > ", large), m.String(); expected != got {
t.Errorf("expected %q, got %q", expected, got)
}
}
func TestCounterAddSmall(t *testing.T) {
counter := NewCounter(CounterOpts{
Name: "test",
Help: "test help",
}).(*counter)
small := 0.000000000001
counter.Add(small)
if expected, got := small, math.Float64frombits(counter.valBits); expected != got {
t.Errorf("valBits expected %f, got %f.", expected, got)
}
if expected, got := uint64(0), counter.valInt; expected != got {
t.Errorf("valInts expected %d, got %d.", expected, got)
}
m := &dto.Metric{}
counter.Write(m)
if expected, got := fmt.Sprintf("counter:<value:%0.0e > ", small), m.String(); expected != got {
t.Errorf("expected %q, got %q", expected, got)
}
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"fmt"
"sort"
"strings"
"github.com/golang/protobuf/proto"
"github.com/prometheus/common/model"
dto "github.com/prometheus/client_model/go"
)
// Desc is the descriptor used by every Prometheus Metric. It is essentially
// the immutable meta-data of a Metric. The normal Metric implementations
// included in this package manage their Desc under the hood. Users only have to
// deal with Desc if they use advanced features like the ExpvarCollector or
// custom Collectors and Metrics.
//
// Descriptors registered with the same registry have to fulfill certain
// consistency and uniqueness criteria if they share the same fully-qualified
// name: They must have the same help string and the same label names (aka label
// dimensions) in each, constLabels and variableLabels, but they must differ in
// the values of the constLabels.
//
// Descriptors that share the same fully-qualified names and the same label
// values of their constLabels are considered equal.
//
// Use NewDesc to create new Desc instances.
type Desc struct {
// fqName has been built from Namespace, Subsystem, and Name.
fqName string
// help provides some helpful information about this metric.
help string
// constLabelPairs contains precalculated DTO label pairs based on
// the constant labels.
constLabelPairs []*dto.LabelPair
// VariableLabels contains names of labels for which the metric
// maintains variable values.
variableLabels []string
// id is a hash of the values of the ConstLabels and fqName. This
// must be unique among all registered descriptors and can therefore be
// used as an identifier of the descriptor.
id uint64
// dimHash is a hash of the label names (preset and variable) and the
// Help string. Each Desc with the same fqName must have the same
// dimHash.
dimHash uint64
// err is an error that occurred during construction. It is reported on
// registration time.
err error
}
// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
// and will be reported on registration time. variableLabels and constLabels can
// be nil if no such labels should be set. fqName and help must not be empty.
//
// variableLabels only contain the label names. Their label values are variable
// and therefore not part of the Desc. (They are managed within the Metric.)
//
// For constLabels, the label values are constant. Therefore, they are fully
// specified in the Desc. See the Collector example for a usage pattern.
func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
d := &Desc{
fqName: fqName,
help: help,
variableLabels: variableLabels,
}
if help == "" {
d.err = errors.New("empty help string")
return d
}
if !model.IsValidMetricName(model.LabelValue(fqName)) {
d.err = fmt.Errorf("%q is not a valid metric name", fqName)
return d
}
// labelValues contains the label values of const labels (in order of
// their sorted label names) plus the fqName (at position 0).
labelValues := make([]string, 1, len(constLabels)+1)
labelValues[0] = fqName
labelNames := make([]string, 0, len(constLabels)+len(variableLabels))
labelNameSet := map[string]struct{}{}
// First add only the const label names and sort them...
for labelName := range constLabels {
if !checkLabelName(labelName) {
d.err = fmt.Errorf("%q is not a valid label name", labelName)
return d
}
labelNames = append(labelNames, labelName)
labelNameSet[labelName] = struct{}{}
}
sort.Strings(labelNames)
// ... so that we can now add const label values in the order of their names.
for _, labelName := range labelNames {
labelValues = append(labelValues, constLabels[labelName])
}
// Validate the const label values. They can't have a wrong cardinality, so
// use in len(labelValues) as expectedNumberOfValues.
if err := validateLabelValues(labelValues, len(labelValues)); err != nil {
d.err = err
return d
}
// Now add the variable label names, but prefix them with something that
// cannot be in a regular label name. That prevents matching the label
// dimension with a different mix between preset and variable labels.
for _, labelName := range variableLabels {
if !checkLabelName(labelName) {
d.err = fmt.Errorf("%q is not a valid label name", labelName)
return d
}
labelNames = append(labelNames, "$"+labelName)
labelNameSet[labelName] = struct{}{}
}
if len(labelNames) != len(labelNameSet) {
d.err = errors.New("duplicate label names")
return d
}
vh := hashNew()
for _, val := range labelValues {
vh = hashAdd(vh, val)
vh = hashAddByte(vh, separatorByte)
}
d.id = vh
// Sort labelNames so that order doesn't matter for the hash.
sort.Strings(labelNames)
// Now hash together (in this order) the help string and the sorted
// label names.
lh := hashNew()
lh = hashAdd(lh, help)
lh = hashAddByte(lh, separatorByte)
for _, labelName := range labelNames {
lh = hashAdd(lh, labelName)
lh = hashAddByte(lh, separatorByte)
}
d.dimHash = lh
d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
for n, v := range constLabels {
d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{
Name: proto.String(n),
Value: proto.String(v),
})
}
sort.Sort(LabelPairSorter(d.constLabelPairs))
return d
}
// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the
// provided error set. If a collector returning such a descriptor is registered,
// registration will fail with the provided error. NewInvalidDesc can be used by
// a Collector to signal inability to describe itself.
func NewInvalidDesc(err error) *Desc {
return &Desc{
err: err,
}
}
func (d *Desc) String() string {
lpStrings := make([]string, 0, len(d.constLabelPairs))
for _, lp := range d.constLabelPairs {
lpStrings = append(
lpStrings,
fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
)
}
return fmt.Sprintf(
"Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: %v}",
d.fqName,
d.help,
strings.Join(lpStrings, ","),
d.variableLabels,
)
}

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package prometheus
import (
"testing"
)
func TestNewDescInvalidLabelValues(t *testing.T) {
desc := NewDesc(
"sample_label",
"sample label",
nil,
Labels{"a": "\xFF"},
)
if desc.err == nil {
t.Errorf("NewDesc: expected error because: %s", desc.err)
}
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package prometheus is the core instrumentation package. It provides metrics
// primitives to instrument code for monitoring. It also offers a registry for
// metrics. Sub-packages allow to expose the registered metrics via HTTP
// (package promhttp) or push them to a Pushgateway (package push). There is
// also a sub-package promauto, which provides metrics constructors with
// automatic registration.
//
// All exported functions and methods are safe to be used concurrently unless
// specified otherwise.
//
// A Basic Example
//
// As a starting point, a very basic usage example:
//
// package main
//
// import (
// "log"
// "net/http"
//
// "github.com/prometheus/client_golang/prometheus"
// "github.com/prometheus/client_golang/prometheus/promhttp"
// )
//
// var (
// cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{
// Name: "cpu_temperature_celsius",
// Help: "Current temperature of the CPU.",
// })
// hdFailures = prometheus.NewCounterVec(
// prometheus.CounterOpts{
// Name: "hd_errors_total",
// Help: "Number of hard-disk errors.",
// },
// []string{"device"},
// )
// )
//
// func init() {
// // Metrics have to be registered to be exposed:
// prometheus.MustRegister(cpuTemp)
// prometheus.MustRegister(hdFailures)
// }
//
// func main() {
// cpuTemp.Set(65.3)
// hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
//
// // The Handler function provides a default handler to expose metrics
// // via an HTTP server. "/metrics" is the usual endpoint for that.
// http.Handle("/metrics", promhttp.Handler())
// log.Fatal(http.ListenAndServe(":8080", nil))
// }
//
//
// This is a complete program that exports two metrics, a Gauge and a Counter,
// the latter with a label attached to turn it into a (one-dimensional) vector.
//
// Metrics
//
// The number of exported identifiers in this package might appear a bit
// overwhelming. However, in addition to the basic plumbing shown in the example
// above, you only need to understand the different metric types and their
// vector versions for basic usage. Furthermore, if you are not concerned with
// fine-grained control of when and how to register metrics with the registry,
// have a look at the promauto package, which will effectively allow you to
// ignore registration altogether in simple cases.
//
// Above, you have already touched the Counter and the Gauge. There are two more
// advanced metric types: the Summary and Histogram. A more thorough description
// of those four metric types can be found in the Prometheus docs:
// https://prometheus.io/docs/concepts/metric_types/
//
// A fifth "type" of metric is Untyped. It behaves like a Gauge, but signals the
// Prometheus server not to assume anything about its type.
//
// In addition to the fundamental metric types Gauge, Counter, Summary,
// Histogram, and Untyped, a very important part of the Prometheus data model is
// the partitioning of samples along dimensions called labels, which results in
// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
// HistogramVec, and UntypedVec.
//
// While only the fundamental metric types implement the Metric interface, both
// the metrics and their vector versions implement the Collector interface. A
// Collector manages the collection of a number of Metrics, but for convenience,
// a Metric can also “collect itself”. Note that Gauge, Counter, Summary,
// Histogram, and Untyped are interfaces themselves while GaugeVec, CounterVec,
// SummaryVec, HistogramVec, and UntypedVec are not.
//
// To create instances of Metrics and their vector versions, you need a suitable
// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, HistogramOpts, or
// UntypedOpts.
//
// Custom Collectors and constant Metrics
//
// While you could create your own implementations of Metric, most likely you
// will only ever implement the Collector interface on your own. At a first
// glance, a custom Collector seems handy to bundle Metrics for common
// registration (with the prime example of the different metric vectors above,
// which bundle all the metrics of the same name but with different labels).
//
// There is a more involved use case, too: If you already have metrics
// available, created outside of the Prometheus context, you don't need the
// interface of the various Metric types. You essentially want to mirror the
// existing numbers into Prometheus Metrics during collection. An own
// implementation of the Collector interface is perfect for that. You can create
// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
// NewConstSummary (and their respective Must… versions). That will happen in
// the Collect method. The Describe method has to return separate Desc
// instances, representative of the “throw-away” metrics to be created later.
// NewDesc comes in handy to create those Desc instances.
//
// The Collector example illustrates the use case. You can also look at the
// source code of the processCollector (mirroring process metrics), the
// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
// metrics) as examples that are used in this package itself.
//
// If you just need to call a function to get a single float value to collect as
// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
// shortcuts.
//
// Advanced Uses of the Registry
//
// While MustRegister is the by far most common way of registering a Collector,
// sometimes you might want to handle the errors the registration might cause.
// As suggested by the name, MustRegister panics if an error occurs. With the
// Register function, the error is returned and can be handled.
//
// An error is returned if the registered Collector is incompatible or
// inconsistent with already registered metrics. The registry aims for
// consistency of the collected metrics according to the Prometheus data model.
// Inconsistencies are ideally detected at registration time, not at collect
// time. The former will usually be detected at start-up time of a program,
// while the latter will only happen at scrape time, possibly not even on the
// first scrape if the inconsistency only becomes relevant later. That is the
// main reason why a Collector and a Metric have to describe themselves to the
// registry.
//
// So far, everything we did operated on the so-called default registry, as it
// can be found in the global DefaultRegisterer variable. With NewRegistry, you
// can create a custom registry, or you can even implement the Registerer or
// Gatherer interfaces yourself. The methods Register and Unregister work in the
// same way on a custom registry as the global functions Register and Unregister
// on the default registry.
//
// There are a number of uses for custom registries: You can use registries with
// special properties, see NewPedanticRegistry. You can avoid global state, as
// it is imposed by the DefaultRegisterer. You can use multiple registries at
// the same time to expose different metrics in different ways. You can use
// separate registries for testing purposes.
//
// Also note that the DefaultRegisterer comes registered with a Collector for Go
// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
// NewProcessCollector). With a custom registry, you are in control and decide
// yourself about the Collectors to register.
//
// HTTP Exposition
//
// The Registry implements the Gatherer interface. The caller of the Gather
// method can then expose the gathered metrics in some way. Usually, the metrics
// are served via HTTP on the /metrics endpoint. That's happening in the example
// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
// (The top-level functions in the prometheus package are deprecated.)
//
// Pushing to the Pushgateway
//
// Function for pushing to the Pushgateway can be found in the push sub-package.
//
// Graphite Bridge
//
// Functions and examples to push metrics from a Gatherer to Graphite can be
// found in the graphite sub-package.
//
// Other Means of Exposition
//
// More ways of exposing metrics can easily be added by following the approaches
// of the existing implementations.
package prometheus

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus_test
import "github.com/prometheus/client_golang/prometheus"
// ClusterManager is an example for a system that might have been built without
// Prometheus in mind. It models a central manager of jobs running in a
// cluster. To turn it into something that collects Prometheus metrics, we
// simply add the two methods required for the Collector interface.
//
// An additional challenge is that multiple instances of the ClusterManager are
// run within the same binary, each in charge of a different zone. We need to
// make use of ConstLabels to be able to register each ClusterManager instance
// with Prometheus.
type ClusterManager struct {
Zone string
OOMCountDesc *prometheus.Desc
RAMUsageDesc *prometheus.Desc
// ... many more fields
}
// ReallyExpensiveAssessmentOfTheSystemState is a mock for the data gathering a
// real cluster manager would have to do. Since it may actually be really
// expensive, it must only be called once per collection. This implementation,
// obviously, only returns some made-up data.
func (c *ClusterManager) ReallyExpensiveAssessmentOfTheSystemState() (
oomCountByHost map[string]int, ramUsageByHost map[string]float64,
) {
// Just example fake data.
oomCountByHost = map[string]int{
"foo.example.org": 42,
"bar.example.org": 2001,
}
ramUsageByHost = map[string]float64{
"foo.example.org": 6.023e23,
"bar.example.org": 3.14,
}
return
}
// Describe simply sends the two Descs in the struct to the channel.
func (c *ClusterManager) Describe(ch chan<- *prometheus.Desc) {
ch <- c.OOMCountDesc
ch <- c.RAMUsageDesc
}
// Collect first triggers the ReallyExpensiveAssessmentOfTheSystemState. Then it
// creates constant metrics for each host on the fly based on the returned data.
//
// Note that Collect could be called concurrently, so we depend on
// ReallyExpensiveAssessmentOfTheSystemState to be concurrency-safe.
func (c *ClusterManager) Collect(ch chan<- prometheus.Metric) {
oomCountByHost, ramUsageByHost := c.ReallyExpensiveAssessmentOfTheSystemState()
for host, oomCount := range oomCountByHost {
ch <- prometheus.MustNewConstMetric(
c.OOMCountDesc,
prometheus.CounterValue,
float64(oomCount),
host,
)
}
for host, ramUsage := range ramUsageByHost {
ch <- prometheus.MustNewConstMetric(
c.RAMUsageDesc,
prometheus.GaugeValue,
ramUsage,
host,
)
}
}
// NewClusterManager creates the two Descs OOMCountDesc and RAMUsageDesc. Note
// that the zone is set as a ConstLabel. (It's different in each instance of the
// ClusterManager, but constant over the lifetime of an instance.) Then there is
// a variable label "host", since we want to partition the collected metrics by
// host. Since all Descs created in this way are consistent across instances,
// with a guaranteed distinction by the "zone" label, we can register different
// ClusterManager instances with the same registry.
func NewClusterManager(zone string) *ClusterManager {
return &ClusterManager{
Zone: zone,
OOMCountDesc: prometheus.NewDesc(
"clustermanager_oom_crashes_total",
"Number of OOM crashes.",
[]string{"host"},
prometheus.Labels{"zone": zone},
),
RAMUsageDesc: prometheus.NewDesc(
"clustermanager_ram_usage_bytes",
"RAM usage as reported to the cluster manager.",
[]string{"host"},
prometheus.Labels{"zone": zone},
),
}
}
func ExampleCollector() {
workerDB := NewClusterManager("db")
workerCA := NewClusterManager("ca")
// Since we are dealing with custom Collector implementations, it might
// be a good idea to try it out with a pedantic registry.
reg := prometheus.NewPedanticRegistry()
reg.MustRegister(workerDB)
reg.MustRegister(workerCA)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus_test
import (
"net/http"
"github.com/prometheus/client_golang/prometheus"
)
var (
// apiRequestDuration tracks the duration separate for each HTTP status
// class (1xx, 2xx, ...). This creates a fair amount of time series on
// the Prometheus server. Usually, you would track the duration of
// serving HTTP request without partitioning by outcome. Do something
// like this only if needed. Also note how only status classes are
// tracked, not every single status code. The latter would create an
// even larger amount of time series. Request counters partitioned by
// status code are usually OK as each counter only creates one time
// series. Histograms are way more expensive, so partition with care and
// only where you really need separate latency tracking. Partitioning by
// status class is only an example. In concrete cases, other partitions
// might make more sense.
apiRequestDuration = prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "api_request_duration_seconds",
Help: "Histogram for the request duration of the public API, partitioned by status class.",
Buckets: prometheus.ExponentialBuckets(0.1, 1.5, 5),
},
[]string{"status_class"},
)
)
func handler(w http.ResponseWriter, r *http.Request) {
status := http.StatusOK
// The ObserverFunc gets called by the deferred ObserveDuration and
// decides which Histogram's Observe method is called.
timer := prometheus.NewTimer(prometheus.ObserverFunc(func(v float64) {
switch {
case status >= 500: // Server error.
apiRequestDuration.WithLabelValues("5xx").Observe(v)
case status >= 400: // Client error.
apiRequestDuration.WithLabelValues("4xx").Observe(v)
case status >= 300: // Redirection.
apiRequestDuration.WithLabelValues("3xx").Observe(v)
case status >= 200: // Success.
apiRequestDuration.WithLabelValues("2xx").Observe(v)
default: // Informational.
apiRequestDuration.WithLabelValues("1xx").Observe(v)
}
}))
defer timer.ObserveDuration()
// Handle the request. Set status accordingly.
// ...
}
func ExampleTimer_complex() {
http.HandleFunc("/api", handler)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus_test
import (
"os"
"github.com/prometheus/client_golang/prometheus"
)
var (
// If a function is called rarely (i.e. not more often than scrapes
// happen) or ideally only once (like in a batch job), it can make sense
// to use a Gauge for timing the function call. For timing a batch job
// and pushing the result to a Pushgateway, see also the comprehensive
// example in the push package.
funcDuration = prometheus.NewGauge(prometheus.GaugeOpts{
Name: "example_function_duration_seconds",
Help: "Duration of the last call of an example function.",
})
)
func run() error {
// The Set method of the Gauge is used to observe the duration.
timer := prometheus.NewTimer(prometheus.ObserverFunc(funcDuration.Set))
defer timer.ObserveDuration()
// Do something. Return errors as encountered. The use of 'defer' above
// makes sure the function is still timed properly.
return nil
}
func ExampleTimer_gauge() {
if err := run(); err != nil {
os.Exit(1)
}
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus_test
import (
"math/rand"
"time"
"github.com/prometheus/client_golang/prometheus"
)
var (
requestDuration = prometheus.NewHistogram(prometheus.HistogramOpts{
Name: "example_request_duration_seconds",
Help: "Histogram for the runtime of a simple example function.",
Buckets: prometheus.LinearBuckets(0.01, 0.01, 10),
})
)
func ExampleTimer() {
// timer times this example function. It uses a Histogram, but a Summary
// would also work, as both implement Observer. Check out
// https://prometheus.io/docs/practices/histograms/ for differences.
timer := prometheus.NewTimer(requestDuration)
defer timer.ObserveDuration()
// Do something here that takes time.
time.Sleep(time.Duration(rand.NormFloat64()*10000+50000) * time.Microsecond)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus_test
import (
"bytes"
"fmt"
"math"
"net/http"
"runtime"
"sort"
"strings"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/common/expfmt"
"github.com/golang/protobuf/proto"
"github.com/prometheus/client_golang/prometheus"
)
func ExampleGauge() {
opsQueued := prometheus.NewGauge(prometheus.GaugeOpts{
Namespace: "our_company",
Subsystem: "blob_storage",
Name: "ops_queued",
Help: "Number of blob storage operations waiting to be processed.",
})
prometheus.MustRegister(opsQueued)
// 10 operations queued by the goroutine managing incoming requests.
opsQueued.Add(10)
// A worker goroutine has picked up a waiting operation.
opsQueued.Dec()
// And once more...
opsQueued.Dec()
}
func ExampleGaugeVec() {
opsQueued := prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: "our_company",
Subsystem: "blob_storage",
Name: "ops_queued",
Help: "Number of blob storage operations waiting to be processed, partitioned by user and type.",
},
[]string{
// Which user has requested the operation?
"user",
// Of what type is the operation?
"type",
},
)
prometheus.MustRegister(opsQueued)
// Increase a value using compact (but order-sensitive!) WithLabelValues().
opsQueued.WithLabelValues("bob", "put").Add(4)
// Increase a value with a map using WithLabels. More verbose, but order
// doesn't matter anymore.
opsQueued.With(prometheus.Labels{"type": "delete", "user": "alice"}).Inc()
}
func ExampleGaugeFunc() {
if err := prometheus.Register(prometheus.NewGaugeFunc(
prometheus.GaugeOpts{
Subsystem: "runtime",
Name: "goroutines_count",
Help: "Number of goroutines that currently exist.",
},
func() float64 { return float64(runtime.NumGoroutine()) },
)); err == nil {
fmt.Println("GaugeFunc 'goroutines_count' registered.")
}
// Note that the count of goroutines is a gauge (and not a counter) as
// it can go up and down.
// Output:
// GaugeFunc 'goroutines_count' registered.
}
func ExampleCounter() {
pushCounter := prometheus.NewCounter(prometheus.CounterOpts{
Name: "repository_pushes", // Note: No help string...
})
err := prometheus.Register(pushCounter) // ... so this will return an error.
if err != nil {
fmt.Println("Push counter couldn't be registered, no counting will happen:", err)
return
}
// Try it once more, this time with a help string.
pushCounter = prometheus.NewCounter(prometheus.CounterOpts{
Name: "repository_pushes",
Help: "Number of pushes to external repository.",
})
err = prometheus.Register(pushCounter)
if err != nil {
fmt.Println("Push counter couldn't be registered AGAIN, no counting will happen:", err)
return
}
pushComplete := make(chan struct{})
// TODO: Start a goroutine that performs repository pushes and reports
// each completion via the channel.
for range pushComplete {
pushCounter.Inc()
}
// Output:
// Push counter couldn't be registered, no counting will happen: descriptor Desc{fqName: "repository_pushes", help: "", constLabels: {}, variableLabels: []} is invalid: empty help string
}
func ExampleCounterVec() {
httpReqs := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "http_requests_total",
Help: "How many HTTP requests processed, partitioned by status code and HTTP method.",
},
[]string{"code", "method"},
)
prometheus.MustRegister(httpReqs)
httpReqs.WithLabelValues("404", "POST").Add(42)
// If you have to access the same set of labels very frequently, it
// might be good to retrieve the metric only once and keep a handle to
// it. But beware of deletion of that metric, see below!
m := httpReqs.WithLabelValues("200", "GET")
for i := 0; i < 1000000; i++ {
m.Inc()
}
// Delete a metric from the vector. If you have previously kept a handle
// to that metric (as above), future updates via that handle will go
// unseen (even if you re-create a metric with the same label set
// later).
httpReqs.DeleteLabelValues("200", "GET")
// Same thing with the more verbose Labels syntax.
httpReqs.Delete(prometheus.Labels{"method": "GET", "code": "200"})
}
func ExampleInstrumentHandler() {
// Handle the "/doc" endpoint with the standard http.FileServer handler.
// By wrapping the handler with InstrumentHandler, request count,
// request and response sizes, and request latency are automatically
// exported to Prometheus, partitioned by HTTP status code and method
// and by the handler name (here "fileserver").
http.Handle("/doc", prometheus.InstrumentHandler(
"fileserver", http.FileServer(http.Dir("/usr/share/doc")),
))
// The Prometheus handler still has to be registered to handle the
// "/metrics" endpoint. The handler returned by prometheus.Handler() is
// already instrumented - with "prometheus" as the handler name. In this
// example, we want the handler name to be "metrics", so we instrument
// the uninstrumented Prometheus handler ourselves.
http.Handle("/metrics", prometheus.InstrumentHandler(
"metrics", prometheus.UninstrumentedHandler(),
))
}
func ExampleLabelPairSorter() {
labelPairs := []*dto.LabelPair{
{Name: proto.String("status"), Value: proto.String("404")},
{Name: proto.String("method"), Value: proto.String("get")},
}
sort.Sort(prometheus.LabelPairSorter(labelPairs))
fmt.Println(labelPairs)
// Output:
// [name:"method" value:"get" name:"status" value:"404" ]
}
func ExampleRegister() {
// Imagine you have a worker pool and want to count the tasks completed.
taskCounter := prometheus.NewCounter(prometheus.CounterOpts{
Subsystem: "worker_pool",
Name: "completed_tasks_total",
Help: "Total number of tasks completed.",
})
// This will register fine.
if err := prometheus.Register(taskCounter); err != nil {
fmt.Println(err)
} else {
fmt.Println("taskCounter registered.")
}
// Don't forget to tell the HTTP server about the Prometheus handler.
// (In a real program, you still need to start the HTTP server...)
http.Handle("/metrics", prometheus.Handler())
// Now you can start workers and give every one of them a pointer to
// taskCounter and let it increment it whenever it completes a task.
taskCounter.Inc() // This has to happen somewhere in the worker code.
// But wait, you want to see how individual workers perform. So you need
// a vector of counters, with one element for each worker.
taskCounterVec := prometheus.NewCounterVec(
prometheus.CounterOpts{
Subsystem: "worker_pool",
Name: "completed_tasks_total",
Help: "Total number of tasks completed.",
},
[]string{"worker_id"},
)
// Registering will fail because we already have a metric of that name.
if err := prometheus.Register(taskCounterVec); err != nil {
fmt.Println("taskCounterVec not registered:", err)
} else {
fmt.Println("taskCounterVec registered.")
}
// To fix, first unregister the old taskCounter.
if prometheus.Unregister(taskCounter) {
fmt.Println("taskCounter unregistered.")
}
// Try registering taskCounterVec again.
if err := prometheus.Register(taskCounterVec); err != nil {
fmt.Println("taskCounterVec not registered:", err)
} else {
fmt.Println("taskCounterVec registered.")
}
// Bummer! Still doesn't work.
// Prometheus will not allow you to ever export metrics with
// inconsistent help strings or label names. After unregistering, the
// unregistered metrics will cease to show up in the /metrics HTTP
// response, but the registry still remembers that those metrics had
// been exported before. For this example, we will now choose a
// different name. (In a real program, you would obviously not export
// the obsolete metric in the first place.)
taskCounterVec = prometheus.NewCounterVec(
prometheus.CounterOpts{
Subsystem: "worker_pool",
Name: "completed_tasks_by_id",
Help: "Total number of tasks completed.",
},
[]string{"worker_id"},
)
if err := prometheus.Register(taskCounterVec); err != nil {
fmt.Println("taskCounterVec not registered:", err)
} else {
fmt.Println("taskCounterVec registered.")
}
// Finally it worked!
// The workers have to tell taskCounterVec their id to increment the
// right element in the metric vector.
taskCounterVec.WithLabelValues("42").Inc() // Code from worker 42.
// Each worker could also keep a reference to their own counter element
// around. Pick the counter at initialization time of the worker.
myCounter := taskCounterVec.WithLabelValues("42") // From worker 42 initialization code.
myCounter.Inc() // Somewhere in the code of that worker.
// Note that something like WithLabelValues("42", "spurious arg") would
// panic (because you have provided too many label values). If you want
// to get an error instead, use GetMetricWithLabelValues(...) instead.
notMyCounter, err := taskCounterVec.GetMetricWithLabelValues("42", "spurious arg")
if err != nil {
fmt.Println("Worker initialization failed:", err)
}
if notMyCounter == nil {
fmt.Println("notMyCounter is nil.")
}
// A different (and somewhat tricky) approach is to use
// ConstLabels. ConstLabels are pairs of label names and label values
// that never change. You might ask what those labels are good for (and
// rightfully so - if they never change, they could as well be part of
// the metric name). There are essentially two use-cases: The first is
// if labels are constant throughout the lifetime of a binary execution,
// but they vary over time or between different instances of a running
// binary. The second is what we have here: Each worker creates and
// registers an own Counter instance where the only difference is in the
// value of the ConstLabels. Those Counters can all be registered
// because the different ConstLabel values guarantee that each worker
// will increment a different Counter metric.
counterOpts := prometheus.CounterOpts{
Subsystem: "worker_pool",
Name: "completed_tasks",
Help: "Total number of tasks completed.",
ConstLabels: prometheus.Labels{"worker_id": "42"},
}
taskCounterForWorker42 := prometheus.NewCounter(counterOpts)
if err := prometheus.Register(taskCounterForWorker42); err != nil {
fmt.Println("taskCounterVForWorker42 not registered:", err)
} else {
fmt.Println("taskCounterForWorker42 registered.")
}
// Obviously, in real code, taskCounterForWorker42 would be a member
// variable of a worker struct, and the "42" would be retrieved with a
// GetId() method or something. The Counter would be created and
// registered in the initialization code of the worker.
// For the creation of the next Counter, we can recycle
// counterOpts. Just change the ConstLabels.
counterOpts.ConstLabels = prometheus.Labels{"worker_id": "2001"}
taskCounterForWorker2001 := prometheus.NewCounter(counterOpts)
if err := prometheus.Register(taskCounterForWorker2001); err != nil {
fmt.Println("taskCounterVForWorker2001 not registered:", err)
} else {
fmt.Println("taskCounterForWorker2001 registered.")
}
taskCounterForWorker2001.Inc()
taskCounterForWorker42.Inc()
taskCounterForWorker2001.Inc()
// Yet another approach would be to turn the workers themselves into
// Collectors and register them. See the Collector example for details.
// Output:
// taskCounter registered.
// taskCounterVec not registered: a previously registered descriptor with the same fully-qualified name as Desc{fqName: "worker_pool_completed_tasks_total", help: "Total number of tasks completed.", constLabels: {}, variableLabels: [worker_id]} has different label names or a different help string
// taskCounter unregistered.
// taskCounterVec not registered: a previously registered descriptor with the same fully-qualified name as Desc{fqName: "worker_pool_completed_tasks_total", help: "Total number of tasks completed.", constLabels: {}, variableLabels: [worker_id]} has different label names or a different help string
// taskCounterVec registered.
// Worker initialization failed: inconsistent label cardinality
// notMyCounter is nil.
// taskCounterForWorker42 registered.
// taskCounterForWorker2001 registered.
}
func ExampleSummary() {
temps := prometheus.NewSummary(prometheus.SummaryOpts{
Name: "pond_temperature_celsius",
Help: "The temperature of the frog pond.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
})
// Simulate some observations.
for i := 0; i < 1000; i++ {
temps.Observe(30 + math.Floor(120*math.Sin(float64(i)*0.1))/10)
}
// Just for demonstration, let's check the state of the summary by
// (ab)using its Write method (which is usually only used by Prometheus
// internally).
metric := &dto.Metric{}
temps.Write(metric)
fmt.Println(proto.MarshalTextString(metric))
// Output:
// summary: <
// sample_count: 1000
// sample_sum: 29969.50000000001
// quantile: <
// quantile: 0.5
// value: 31.1
// >
// quantile: <
// quantile: 0.9
// value: 41.3
// >
// quantile: <
// quantile: 0.99
// value: 41.9
// >
// >
}
func ExampleSummaryVec() {
temps := prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "pond_temperature_celsius",
Help: "The temperature of the frog pond.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"species"},
)
// Simulate some observations.
for i := 0; i < 1000; i++ {
temps.WithLabelValues("litoria-caerulea").Observe(30 + math.Floor(120*math.Sin(float64(i)*0.1))/10)
temps.WithLabelValues("lithobates-catesbeianus").Observe(32 + math.Floor(100*math.Cos(float64(i)*0.11))/10)
}
// Create a Summary without any observations.
temps.WithLabelValues("leiopelma-hochstetteri")
// Just for demonstration, let's check the state of the summary vector
// by registering it with a custom registry and then let it collect the
// metrics.
reg := prometheus.NewRegistry()
reg.MustRegister(temps)
metricFamilies, err := reg.Gather()
if err != nil || len(metricFamilies) != 1 {
panic("unexpected behavior of custom test registry")
}
fmt.Println(proto.MarshalTextString(metricFamilies[0]))
// Output:
// name: "pond_temperature_celsius"
// help: "The temperature of the frog pond."
// type: SUMMARY
// metric: <
// label: <
// name: "species"
// value: "leiopelma-hochstetteri"
// >
// summary: <
// sample_count: 0
// sample_sum: 0
// quantile: <
// quantile: 0.5
// value: nan
// >
// quantile: <
// quantile: 0.9
// value: nan
// >
// quantile: <
// quantile: 0.99
// value: nan
// >
// >
// >
// metric: <
// label: <
// name: "species"
// value: "lithobates-catesbeianus"
// >
// summary: <
// sample_count: 1000
// sample_sum: 31956.100000000017
// quantile: <
// quantile: 0.5
// value: 32.4
// >
// quantile: <
// quantile: 0.9
// value: 41.4
// >
// quantile: <
// quantile: 0.99
// value: 41.9
// >
// >
// >
// metric: <
// label: <
// name: "species"
// value: "litoria-caerulea"
// >
// summary: <
// sample_count: 1000
// sample_sum: 29969.50000000001
// quantile: <
// quantile: 0.5
// value: 31.1
// >
// quantile: <
// quantile: 0.9
// value: 41.3
// >
// quantile: <
// quantile: 0.99
// value: 41.9
// >
// >
// >
}
func ExampleNewConstSummary() {
desc := prometheus.NewDesc(
"http_request_duration_seconds",
"A summary of the HTTP request durations.",
[]string{"code", "method"},
prometheus.Labels{"owner": "example"},
)
// Create a constant summary from values we got from a 3rd party telemetry system.
s := prometheus.MustNewConstSummary(
desc,
4711, 403.34,
map[float64]float64{0.5: 42.3, 0.9: 323.3},
"200", "get",
)
// Just for demonstration, let's check the state of the summary by
// (ab)using its Write method (which is usually only used by Prometheus
// internally).
metric := &dto.Metric{}
s.Write(metric)
fmt.Println(proto.MarshalTextString(metric))
// Output:
// label: <
// name: "code"
// value: "200"
// >
// label: <
// name: "method"
// value: "get"
// >
// label: <
// name: "owner"
// value: "example"
// >
// summary: <
// sample_count: 4711
// sample_sum: 403.34
// quantile: <
// quantile: 0.5
// value: 42.3
// >
// quantile: <
// quantile: 0.9
// value: 323.3
// >
// >
}
func ExampleHistogram() {
temps := prometheus.NewHistogram(prometheus.HistogramOpts{
Name: "pond_temperature_celsius",
Help: "The temperature of the frog pond.", // Sorry, we can't measure how badly it smells.
Buckets: prometheus.LinearBuckets(20, 5, 5), // 5 buckets, each 5 centigrade wide.
})
// Simulate some observations.
for i := 0; i < 1000; i++ {
temps.Observe(30 + math.Floor(120*math.Sin(float64(i)*0.1))/10)
}
// Just for demonstration, let's check the state of the histogram by
// (ab)using its Write method (which is usually only used by Prometheus
// internally).
metric := &dto.Metric{}
temps.Write(metric)
fmt.Println(proto.MarshalTextString(metric))
// Output:
// histogram: <
// sample_count: 1000
// sample_sum: 29969.50000000001
// bucket: <
// cumulative_count: 192
// upper_bound: 20
// >
// bucket: <
// cumulative_count: 366
// upper_bound: 25
// >
// bucket: <
// cumulative_count: 501
// upper_bound: 30
// >
// bucket: <
// cumulative_count: 638
// upper_bound: 35
// >
// bucket: <
// cumulative_count: 816
// upper_bound: 40
// >
// >
}
func ExampleNewConstHistogram() {
desc := prometheus.NewDesc(
"http_request_duration_seconds",
"A histogram of the HTTP request durations.",
[]string{"code", "method"},
prometheus.Labels{"owner": "example"},
)
// Create a constant histogram from values we got from a 3rd party telemetry system.
h := prometheus.MustNewConstHistogram(
desc,
4711, 403.34,
map[float64]uint64{25: 121, 50: 2403, 100: 3221, 200: 4233},
"200", "get",
)
// Just for demonstration, let's check the state of the histogram by
// (ab)using its Write method (which is usually only used by Prometheus
// internally).
metric := &dto.Metric{}
h.Write(metric)
fmt.Println(proto.MarshalTextString(metric))
// Output:
// label: <
// name: "code"
// value: "200"
// >
// label: <
// name: "method"
// value: "get"
// >
// label: <
// name: "owner"
// value: "example"
// >
// histogram: <
// sample_count: 4711
// sample_sum: 403.34
// bucket: <
// cumulative_count: 121
// upper_bound: 25
// >
// bucket: <
// cumulative_count: 2403
// upper_bound: 50
// >
// bucket: <
// cumulative_count: 3221
// upper_bound: 100
// >
// bucket: <
// cumulative_count: 4233
// upper_bound: 200
// >
// >
}
func ExampleAlreadyRegisteredError() {
reqCounter := prometheus.NewCounter(prometheus.CounterOpts{
Name: "requests_total",
Help: "The total number of requests served.",
})
if err := prometheus.Register(reqCounter); err != nil {
if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
// A counter for that metric has been registered before.
// Use the old counter from now on.
reqCounter = are.ExistingCollector.(prometheus.Counter)
} else {
// Something else went wrong!
panic(err)
}
}
reqCounter.Inc()
}
func ExampleGatherers() {
reg := prometheus.NewRegistry()
temp := prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Name: "temperature_kelvin",
Help: "Temperature in Kelvin.",
},
[]string{"location"},
)
reg.MustRegister(temp)
temp.WithLabelValues("outside").Set(273.14)
temp.WithLabelValues("inside").Set(298.44)
var parser expfmt.TextParser
text := `
# TYPE humidity_percent gauge
# HELP humidity_percent Humidity in %.
humidity_percent{location="outside"} 45.4
humidity_percent{location="inside"} 33.2
# TYPE temperature_kelvin gauge
# HELP temperature_kelvin Temperature in Kelvin.
temperature_kelvin{location="somewhere else"} 4.5
`
parseText := func() ([]*dto.MetricFamily, error) {
parsed, err := parser.TextToMetricFamilies(strings.NewReader(text))
if err != nil {
return nil, err
}
var result []*dto.MetricFamily
for _, mf := range parsed {
result = append(result, mf)
}
return result, nil
}
gatherers := prometheus.Gatherers{
reg,
prometheus.GathererFunc(parseText),
}
gathering, err := gatherers.Gather()
if err != nil {
fmt.Println(err)
}
out := &bytes.Buffer{}
for _, mf := range gathering {
if _, err := expfmt.MetricFamilyToText(out, mf); err != nil {
panic(err)
}
}
fmt.Print(out.String())
fmt.Println("----------")
// Note how the temperature_kelvin metric family has been merged from
// different sources. Now try
text = `
# TYPE humidity_percent gauge
# HELP humidity_percent Humidity in %.
humidity_percent{location="outside"} 45.4
humidity_percent{location="inside"} 33.2
# TYPE temperature_kelvin gauge
# HELP temperature_kelvin Temperature in Kelvin.
# Duplicate metric:
temperature_kelvin{location="outside"} 265.3
# Wrong labels:
temperature_kelvin 4.5
`
gathering, err = gatherers.Gather()
if err != nil {
fmt.Println(err)
}
// Note that still as many metrics as possible are returned:
out.Reset()
for _, mf := range gathering {
if _, err := expfmt.MetricFamilyToText(out, mf); err != nil {
panic(err)
}
}
fmt.Print(out.String())
// Output:
// # HELP humidity_percent Humidity in %.
// # TYPE humidity_percent gauge
// humidity_percent{location="inside"} 33.2
// humidity_percent{location="outside"} 45.4
// # HELP temperature_kelvin Temperature in Kelvin.
// # TYPE temperature_kelvin gauge
// temperature_kelvin{location="inside"} 298.44
// temperature_kelvin{location="outside"} 273.14
// temperature_kelvin{location="somewhere else"} 4.5
// ----------
// 2 error(s) occurred:
// * collected metric temperature_kelvin label:<name:"location" value:"outside" > gauge:<value:265.3 > was collected before with the same name and label values
// * collected metric temperature_kelvin gauge:<value:4.5 > has label dimensions inconsistent with previously collected metrics in the same metric family
// # HELP humidity_percent Humidity in %.
// # TYPE humidity_percent gauge
// humidity_percent{location="inside"} 33.2
// humidity_percent{location="outside"} 45.4
// # HELP temperature_kelvin Temperature in Kelvin.
// # TYPE temperature_kelvin gauge
// temperature_kelvin{location="inside"} 298.44
// temperature_kelvin{location="outside"} 273.14
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"encoding/json"
"expvar"
)
type expvarCollector struct {
exports map[string]*Desc
}
// NewExpvarCollector returns a newly allocated expvar Collector that still has
// to be registered with a Prometheus registry.
//
// An expvar Collector collects metrics from the expvar interface. It provides a
// quick way to expose numeric values that are already exported via expvar as
// Prometheus metrics. Note that the data models of expvar and Prometheus are
// fundamentally different, and that the expvar Collector is inherently slower
// than native Prometheus metrics. Thus, the expvar Collector is probably great
// for experiments and prototying, but you should seriously consider a more
// direct implementation of Prometheus metrics for monitoring production
// systems.
//
// The exports map has the following meaning:
//
// The keys in the map correspond to expvar keys, i.e. for every expvar key you
// want to export as Prometheus metric, you need an entry in the exports
// map. The descriptor mapped to each key describes how to export the expvar
// value. It defines the name and the help string of the Prometheus metric
// proxying the expvar value. The type will always be Untyped.
//
// For descriptors without variable labels, the expvar value must be a number or
// a bool. The number is then directly exported as the Prometheus sample
// value. (For a bool, 'false' translates to 0 and 'true' to 1). Expvar values
// that are not numbers or bools are silently ignored.
//
// If the descriptor has one variable label, the expvar value must be an expvar
// map. The keys in the expvar map become the various values of the one
// Prometheus label. The values in the expvar map must be numbers or bools again
// as above.
//
// For descriptors with more than one variable label, the expvar must be a
// nested expvar map, i.e. where the values of the topmost map are maps again
// etc. until a depth is reached that corresponds to the number of labels. The
// leaves of that structure must be numbers or bools as above to serve as the
// sample values.
//
// Anything that does not fit into the scheme above is silently ignored.
func NewExpvarCollector(exports map[string]*Desc) Collector {
return &expvarCollector{
exports: exports,
}
}
// Describe implements Collector.
func (e *expvarCollector) Describe(ch chan<- *Desc) {
for _, desc := range e.exports {
ch <- desc
}
}
// Collect implements Collector.
func (e *expvarCollector) Collect(ch chan<- Metric) {
for name, desc := range e.exports {
var m Metric
expVar := expvar.Get(name)
if expVar == nil {
continue
}
var v interface{}
labels := make([]string, len(desc.variableLabels))
if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil {
ch <- NewInvalidMetric(desc, err)
continue
}
var processValue func(v interface{}, i int)
processValue = func(v interface{}, i int) {
if i >= len(labels) {
copiedLabels := append(make([]string, 0, len(labels)), labels...)
switch v := v.(type) {
case float64:
m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...)
case bool:
if v {
m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...)
} else {
m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...)
}
default:
return
}
ch <- m
return
}
vm, ok := v.(map[string]interface{})
if !ok {
return
}
for lv, val := range vm {
labels[i] = lv
processValue(val, i+1)
}
}
processValue(v, 0)
}
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus_test
import (
"expvar"
"fmt"
"sort"
"strings"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/client_golang/prometheus"
)
func ExampleNewExpvarCollector() {
expvarCollector := prometheus.NewExpvarCollector(map[string]*prometheus.Desc{
"memstats": prometheus.NewDesc(
"expvar_memstats",
"All numeric memstats as one metric family. Not a good role-model, actually... ;-)",
[]string{"type"}, nil,
),
"lone-int": prometheus.NewDesc(
"expvar_lone_int",
"Just an expvar int as an example.",
nil, nil,
),
"http-request-map": prometheus.NewDesc(
"expvar_http_request_total",
"How many http requests processed, partitioned by status code and http method.",
[]string{"code", "method"}, nil,
),
})
prometheus.MustRegister(expvarCollector)
// The Prometheus part is done here. But to show that this example is
// doing anything, we have to manually export something via expvar. In
// real-life use-cases, some library would already have exported via
// expvar what we want to re-export as Prometheus metrics.
expvar.NewInt("lone-int").Set(42)
expvarMap := expvar.NewMap("http-request-map")
var (
expvarMap1, expvarMap2 expvar.Map
expvarInt11, expvarInt12, expvarInt21, expvarInt22 expvar.Int
)
expvarMap1.Init()
expvarMap2.Init()
expvarInt11.Set(3)
expvarInt12.Set(13)
expvarInt21.Set(11)
expvarInt22.Set(212)
expvarMap1.Set("POST", &expvarInt11)
expvarMap1.Set("GET", &expvarInt12)
expvarMap2.Set("POST", &expvarInt21)
expvarMap2.Set("GET", &expvarInt22)
expvarMap.Set("404", &expvarMap1)
expvarMap.Set("200", &expvarMap2)
// Results in the following expvar map:
// "http-request-count": {"200": {"POST": 11, "GET": 212}, "404": {"POST": 3, "GET": 13}}
// Let's see what the scrape would yield, but exclude the memstats metrics.
metricStrings := []string{}
metric := dto.Metric{}
metricChan := make(chan prometheus.Metric)
go func() {
expvarCollector.Collect(metricChan)
close(metricChan)
}()
for m := range metricChan {
if !strings.Contains(m.Desc().String(), "expvar_memstats") {
metric.Reset()
m.Write(&metric)
metricStrings = append(metricStrings, metric.String())
}
}
sort.Strings(metricStrings)
for _, s := range metricStrings {
fmt.Println(strings.TrimRight(s, " "))
}
// Output:
// label:<name:"code" value:"200" > label:<name:"method" value:"GET" > untyped:<value:212 >
// label:<name:"code" value:"200" > label:<name:"method" value:"POST" > untyped:<value:11 >
// label:<name:"code" value:"404" > label:<name:"method" value:"GET" > untyped:<value:13 >
// label:<name:"code" value:"404" > label:<name:"method" value:"POST" > untyped:<value:3 >
// untyped:<value:42 >
}

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package prometheus
// Inline and byte-free variant of hash/fnv's fnv64a.
const (
offset64 = 14695981039346656037
prime64 = 1099511628211
)
// hashNew initializies a new fnv64a hash value.
func hashNew() uint64 {
return offset64
}
// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
func hashAdd(h uint64, s string) uint64 {
for i := 0; i < len(s); i++ {
h ^= uint64(s[i])
h *= prime64
}
return h
}
// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
func hashAddByte(h uint64, b byte) uint64 {
h ^= uint64(b)
h *= prime64
return h
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"math"
"sync/atomic"
"time"
dto "github.com/prometheus/client_model/go"
)
// Gauge is a Metric that represents a single numerical value that can
// arbitrarily go up and down.
//
// A Gauge is typically used for measured values like temperatures or current
// memory usage, but also "counts" that can go up and down, like the number of
// running goroutines.
//
// To create Gauge instances, use NewGauge.
type Gauge interface {
Metric
Collector
// Set sets the Gauge to an arbitrary value.
Set(float64)
// Inc increments the Gauge by 1. Use Add to increment it by arbitrary
// values.
Inc()
// Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary
// values.
Dec()
// Add adds the given value to the Gauge. (The value can be negative,
// resulting in a decrease of the Gauge.)
Add(float64)
// Sub subtracts the given value from the Gauge. (The value can be
// negative, resulting in an increase of the Gauge.)
Sub(float64)
// SetToCurrentTime sets the Gauge to the current Unix time in seconds.
SetToCurrentTime()
}
// GaugeOpts is an alias for Opts. See there for doc comments.
type GaugeOpts Opts
// NewGauge creates a new Gauge based on the provided GaugeOpts.
//
// The returned implementation is optimized for a fast Set method. If you have a
// choice for managing the value of a Gauge via Set vs. Inc/Dec/Add/Sub, pick
// the former. For example, the Inc method of the returned Gauge is slower than
// the Inc method of a Counter returned by NewCounter. This matches the typical
// scenarios for Gauges and Counters, where the former tends to be Set-heavy and
// the latter Inc-heavy.
func NewGauge(opts GaugeOpts) Gauge {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
)
result := &gauge{desc: desc, labelPairs: desc.constLabelPairs}
result.init(result) // Init self-collection.
return result
}
type gauge struct {
// valBits contains the bits of the represented float64 value. It has
// to go first in the struct to guarantee alignment for atomic
// operations. http://golang.org/pkg/sync/atomic/#pkg-note-BUG
valBits uint64
selfCollector
desc *Desc
labelPairs []*dto.LabelPair
}
func (g *gauge) Desc() *Desc {
return g.desc
}
func (g *gauge) Set(val float64) {
atomic.StoreUint64(&g.valBits, math.Float64bits(val))
}
func (g *gauge) SetToCurrentTime() {
g.Set(float64(time.Now().UnixNano()) / 1e9)
}
func (g *gauge) Inc() {
g.Add(1)
}
func (g *gauge) Dec() {
g.Add(-1)
}
func (g *gauge) Add(val float64) {
for {
oldBits := atomic.LoadUint64(&g.valBits)
newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
if atomic.CompareAndSwapUint64(&g.valBits, oldBits, newBits) {
return
}
}
}
func (g *gauge) Sub(val float64) {
g.Add(val * -1)
}
func (g *gauge) Write(out *dto.Metric) error {
val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
return populateMetric(GaugeValue, val, g.labelPairs, out)
}
// GaugeVec is a Collector that bundles a set of Gauges that all share the same
// Desc, but have different values for their variable labels. This is used if
// you want to count the same thing partitioned by various dimensions
// (e.g. number of operations queued, partitioned by user and operation
// type). Create instances with NewGaugeVec.
type GaugeVec struct {
*metricVec
}
// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
// partitioned by the given label names.
func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &GaugeVec{
metricVec: newMetricVec(desc, func(lvs ...string) Metric {
if len(lvs) != len(desc.variableLabels) {
panic(errInconsistentCardinality)
}
result := &gauge{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
result.init(result) // Init self-collection.
return result
}),
}
}
// GetMetricWithLabelValues returns the Gauge for the given slice of label
// values (same order as the VariableLabels in Desc). If that combination of
// label values is accessed for the first time, a new Gauge is created.
//
// It is possible to call this method without using the returned Gauge to only
// create the new Gauge but leave it at its starting value 0. See also the
// SummaryVec example.
//
// Keeping the Gauge for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Gauge from the GaugeVec. In that case, the
// Gauge will still exist, but it will not be exported anymore, even if a
// Gauge with the same label values is created later. See also the CounterVec
// example.
//
// An error is returned if the number of label values is not the same as the
// number of VariableLabels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Gauge), err
}
return nil, err
}
// GetMetricWith returns the Gauge for the given Labels map (the label names
// must match those of the VariableLabels in Desc). If that label map is
// accessed for the first time, a new Gauge is created. Implications of
// creating a Gauge without using it and keeping the Gauge for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Gauge), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
// myVec.WithLabelValues("404", "GET").Add(42)
func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
g, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return g
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
func (v *GaugeVec) With(labels Labels) Gauge {
g, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return g
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the GaugeVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &GaugeVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
// GaugeFunc is a Gauge whose value is determined at collect time by calling a
// provided function.
//
// To create GaugeFunc instances, use NewGaugeFunc.
type GaugeFunc interface {
Metric
Collector
}
// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
// value reported is determined by calling the given function from within the
// Write method. Take into account that metric collection may happen
// concurrently. If that results in concurrent calls to Write, like in the case
// where a GaugeFunc is directly registered with Prometheus, the provided
// function must be concurrency-safe.
func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), GaugeValue, function)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"math"
"math/rand"
"sync"
"testing"
"testing/quick"
"time"
dto "github.com/prometheus/client_model/go"
)
func listenGaugeStream(vals, result chan float64, done chan struct{}) {
var sum float64
outer:
for {
select {
case <-done:
close(vals)
for v := range vals {
sum += v
}
break outer
case v := <-vals:
sum += v
}
}
result <- sum
close(result)
}
func TestGaugeConcurrency(t *testing.T) {
it := func(n uint32) bool {
mutations := int(n % 10000)
concLevel := int(n%15 + 1)
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
sStream := make(chan float64, mutations*concLevel)
result := make(chan float64)
done := make(chan struct{})
go listenGaugeStream(sStream, result, done)
go func() {
end.Wait()
close(done)
}()
gge := NewGauge(GaugeOpts{
Name: "test_gauge",
Help: "no help can be found here",
})
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
for j := 0; j < mutations; j++ {
vals[j] = rand.Float64() - 0.5
}
go func(vals []float64) {
start.Wait()
for _, v := range vals {
sStream <- v
gge.Add(v)
}
end.Done()
}(vals)
}
start.Done()
if expected, got := <-result, math.Float64frombits(gge.(*gauge).valBits); math.Abs(expected-got) > 0.000001 {
t.Fatalf("expected approx. %f, got %f", expected, got)
return false
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Fatal(err)
}
}
func TestGaugeVecConcurrency(t *testing.T) {
it := func(n uint32) bool {
mutations := int(n % 10000)
concLevel := int(n%15 + 1)
vecLength := int(n%5 + 1)
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
sStreams := make([]chan float64, vecLength)
results := make([]chan float64, vecLength)
done := make(chan struct{})
for i := 0; i < vecLength; i++ {
sStreams[i] = make(chan float64, mutations*concLevel)
results[i] = make(chan float64)
go listenGaugeStream(sStreams[i], results[i], done)
}
go func() {
end.Wait()
close(done)
}()
gge := NewGaugeVec(
GaugeOpts{
Name: "test_gauge",
Help: "no help can be found here",
},
[]string{"label"},
)
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
pick := make([]int, mutations)
for j := 0; j < mutations; j++ {
vals[j] = rand.Float64() - 0.5
pick[j] = rand.Intn(vecLength)
}
go func(vals []float64) {
start.Wait()
for i, v := range vals {
sStreams[pick[i]] <- v
gge.WithLabelValues(string('A' + pick[i])).Add(v)
}
end.Done()
}(vals)
}
start.Done()
for i := range sStreams {
if expected, got := <-results[i], math.Float64frombits(gge.WithLabelValues(string('A'+i)).(*gauge).valBits); math.Abs(expected-got) > 0.000001 {
t.Fatalf("expected approx. %f, got %f", expected, got)
return false
}
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Fatal(err)
}
}
func TestGaugeFunc(t *testing.T) {
gf := NewGaugeFunc(
GaugeOpts{
Name: "test_name",
Help: "test help",
ConstLabels: Labels{"a": "1", "b": "2"},
},
func() float64 { return 3.1415 },
)
if expected, got := `Desc{fqName: "test_name", help: "test help", constLabels: {a="1",b="2"}, variableLabels: []}`, gf.Desc().String(); expected != got {
t.Errorf("expected %q, got %q", expected, got)
}
m := &dto.Metric{}
gf.Write(m)
if expected, got := `label:<name:"a" value:"1" > label:<name:"b" value:"2" > gauge:<value:3.1415 > `, m.String(); expected != got {
t.Errorf("expected %q, got %q", expected, got)
}
}
func TestGaugeSetCurrentTime(t *testing.T) {
g := NewGauge(GaugeOpts{
Name: "test_name",
Help: "test help",
})
g.SetToCurrentTime()
unixTime := float64(time.Now().Unix())
m := &dto.Metric{}
g.Write(m)
delta := unixTime - m.GetGauge().GetValue()
// This is just a smoke test to make sure SetToCurrentTime is not
// totally off. Tests with current time involved are hard...
if math.Abs(delta) > 5 {
t.Errorf("Gauge set to current time deviates from current time by more than 5s, delta is %f seconds", delta)
}
}

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package prometheus
import (
"fmt"
"runtime"
"runtime/debug"
"time"
)
type goCollector struct {
goroutinesDesc *Desc
threadsDesc *Desc
gcDesc *Desc
goInfoDesc *Desc
// metrics to describe and collect
metrics memStatsMetrics
}
// NewGoCollector returns a collector which exports metrics about the current Go
// process. This includes memory stats. To collect those, runtime.ReadMemStats
// is called. This causes a stop-the-world, which is very short with Go1.9+
// (~25µs). However, with older Go versions, the stop-the-world duration depends
// on the heap size and can be quite significant (~1.7 ms/GiB as per
// https://go-review.googlesource.com/c/go/+/34937).
func NewGoCollector() Collector {
return &goCollector{
goroutinesDesc: NewDesc(
"go_goroutines",
"Number of goroutines that currently exist.",
nil, nil),
threadsDesc: NewDesc(
"go_threads",
"Number of OS threads created.",
nil, nil),
gcDesc: NewDesc(
"go_gc_duration_seconds",
"A summary of the GC invocation durations.",
nil, nil),
goInfoDesc: NewDesc(
"go_info",
"Information about the Go environment.",
nil, Labels{"version": runtime.Version()}),
metrics: memStatsMetrics{
{
desc: NewDesc(
memstatNamespace("alloc_bytes"),
"Number of bytes allocated and still in use.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("alloc_bytes_total"),
"Total number of bytes allocated, even if freed.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("sys_bytes"),
"Number of bytes obtained from system.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("lookups_total"),
"Total number of pointer lookups.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("mallocs_total"),
"Total number of mallocs.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("frees_total"),
"Total number of frees.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("heap_alloc_bytes"),
"Number of heap bytes allocated and still in use.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_sys_bytes"),
"Number of heap bytes obtained from system.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_idle_bytes"),
"Number of heap bytes waiting to be used.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_inuse_bytes"),
"Number of heap bytes that are in use.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_released_bytes"),
"Number of heap bytes released to OS.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_objects"),
"Number of allocated objects.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("stack_inuse_bytes"),
"Number of bytes in use by the stack allocator.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("stack_sys_bytes"),
"Number of bytes obtained from system for stack allocator.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mspan_inuse_bytes"),
"Number of bytes in use by mspan structures.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mspan_sys_bytes"),
"Number of bytes used for mspan structures obtained from system.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mcache_inuse_bytes"),
"Number of bytes in use by mcache structures.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mcache_sys_bytes"),
"Number of bytes used for mcache structures obtained from system.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("buck_hash_sys_bytes"),
"Number of bytes used by the profiling bucket hash table.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("gc_sys_bytes"),
"Number of bytes used for garbage collection system metadata.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("other_sys_bytes"),
"Number of bytes used for other system allocations.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("next_gc_bytes"),
"Number of heap bytes when next garbage collection will take place.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("last_gc_time_seconds"),
"Number of seconds since 1970 of last garbage collection.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("gc_cpu_fraction"),
"The fraction of this program's available CPU time used by the GC since the program started.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
valType: GaugeValue,
},
},
}
}
func memstatNamespace(s string) string {
return fmt.Sprintf("go_memstats_%s", s)
}
// Describe returns all descriptions of the collector.
func (c *goCollector) Describe(ch chan<- *Desc) {
ch <- c.goroutinesDesc
ch <- c.threadsDesc
ch <- c.gcDesc
ch <- c.goInfoDesc
for _, i := range c.metrics {
ch <- i.desc
}
}
// Collect returns the current state of all metrics of the collector.
func (c *goCollector) Collect(ch chan<- Metric) {
ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
n, _ := runtime.ThreadCreateProfile(nil)
ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, float64(n))
var stats debug.GCStats
stats.PauseQuantiles = make([]time.Duration, 5)
debug.ReadGCStats(&stats)
quantiles := make(map[float64]float64)
for idx, pq := range stats.PauseQuantiles[1:] {
quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
}
quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), stats.PauseTotal.Seconds(), quantiles)
ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
ms := &runtime.MemStats{}
runtime.ReadMemStats(ms)
for _, i := range c.metrics {
ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
}
}
// memStatsMetrics provide description, value, and value type for memstat metrics.
type memStatsMetrics []struct {
desc *Desc
eval func(*runtime.MemStats) float64
valType ValueType
}

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package prometheus
import (
"runtime"
"testing"
"time"
dto "github.com/prometheus/client_model/go"
)
func TestGoCollector(t *testing.T) {
var (
c = NewGoCollector()
ch = make(chan Metric)
waitc = make(chan struct{})
closec = make(chan struct{})
old = -1
)
defer close(closec)
go func() {
c.Collect(ch)
go func(c <-chan struct{}) {
<-c
}(closec)
<-waitc
c.Collect(ch)
}()
for {
select {
case m := <-ch:
// m can be Gauge or Counter,
// currently just test the go_goroutines Gauge
// and ignore others.
if m.Desc().fqName != "go_goroutines" {
continue
}
pb := &dto.Metric{}
m.Write(pb)
if pb.GetGauge() == nil {
continue
}
if old == -1 {
old = int(pb.GetGauge().GetValue())
close(waitc)
continue
}
if diff := int(pb.GetGauge().GetValue()) - old; diff != 1 {
// TODO: This is flaky in highly concurrent situations.
t.Errorf("want 1 new goroutine, got %d", diff)
}
// GoCollector performs three sends per call.
// On line 27 we need to receive three more sends
// to shut down cleanly.
<-ch
<-ch
<-ch
return
case <-time.After(1 * time.Second):
t.Fatalf("expected collect timed out")
}
}
}
func TestGCCollector(t *testing.T) {
var (
c = NewGoCollector()
ch = make(chan Metric)
waitc = make(chan struct{})
closec = make(chan struct{})
oldGC uint64
oldPause float64
)
defer close(closec)
go func() {
c.Collect(ch)
// force GC
runtime.GC()
<-waitc
c.Collect(ch)
}()
first := true
for {
select {
case metric := <-ch:
pb := &dto.Metric{}
metric.Write(pb)
if pb.GetSummary() == nil {
continue
}
if len(pb.GetSummary().Quantile) != 5 {
t.Errorf("expected 4 buckets, got %d", len(pb.GetSummary().Quantile))
}
for idx, want := range []float64{0.0, 0.25, 0.5, 0.75, 1.0} {
if *pb.GetSummary().Quantile[idx].Quantile != want {
t.Errorf("bucket #%d is off, got %f, want %f", idx, *pb.GetSummary().Quantile[idx].Quantile, want)
}
}
if first {
first = false
oldGC = *pb.GetSummary().SampleCount
oldPause = *pb.GetSummary().SampleSum
close(waitc)
continue
}
if diff := *pb.GetSummary().SampleCount - oldGC; diff != 1 {
t.Errorf("want 1 new garbage collection run, got %d", diff)
}
if diff := *pb.GetSummary().SampleSum - oldPause; diff <= 0 {
t.Errorf("want moar pause, got %f", diff)
}
return
case <-time.After(1 * time.Second):
t.Fatalf("expected collect timed out")
}
}
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package graphite provides a bridge to push Prometheus metrics to a Graphite
// server.
package graphite
import (
"bufio"
"errors"
"fmt"
"io"
"net"
"sort"
"time"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/common/model"
"golang.org/x/net/context"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/client_golang/prometheus"
)
const (
defaultInterval = 15 * time.Second
millisecondsPerSecond = 1000
)
// HandlerErrorHandling defines how a Handler serving metrics will handle
// errors.
type HandlerErrorHandling int
// These constants cause handlers serving metrics to behave as described if
// errors are encountered.
const (
// Ignore errors and try to push as many metrics to Graphite as possible.
ContinueOnError HandlerErrorHandling = iota
// Abort the push to Graphite upon the first error encountered.
AbortOnError
)
// Config defines the Graphite bridge config.
type Config struct {
// The url to push data to. Required.
URL string
// The prefix for the pushed Graphite metrics. Defaults to empty string.
Prefix string
// The interval to use for pushing data to Graphite. Defaults to 15 seconds.
Interval time.Duration
// The timeout for pushing metrics to Graphite. Defaults to 15 seconds.
Timeout time.Duration
// The Gatherer to use for metrics. Defaults to prometheus.DefaultGatherer.
Gatherer prometheus.Gatherer
// The logger that messages are written to. Defaults to no logging.
Logger Logger
// ErrorHandling defines how errors are handled. Note that errors are
// logged regardless of the configured ErrorHandling provided Logger
// is not nil.
ErrorHandling HandlerErrorHandling
}
// Bridge pushes metrics to the configured Graphite server.
type Bridge struct {
url string
prefix string
interval time.Duration
timeout time.Duration
errorHandling HandlerErrorHandling
logger Logger
g prometheus.Gatherer
}
// Logger is the minimal interface Bridge needs for logging. Note that
// log.Logger from the standard library implements this interface, and it is
// easy to implement by custom loggers, if they don't do so already anyway.
type Logger interface {
Println(v ...interface{})
}
// NewBridge returns a pointer to a new Bridge struct.
func NewBridge(c *Config) (*Bridge, error) {
b := &Bridge{}
if c.URL == "" {
return nil, errors.New("missing URL")
}
b.url = c.URL
if c.Gatherer == nil {
b.g = prometheus.DefaultGatherer
} else {
b.g = c.Gatherer
}
if c.Logger != nil {
b.logger = c.Logger
}
if c.Prefix != "" {
b.prefix = c.Prefix
}
var z time.Duration
if c.Interval == z {
b.interval = defaultInterval
} else {
b.interval = c.Interval
}
if c.Timeout == z {
b.timeout = defaultInterval
} else {
b.timeout = c.Timeout
}
b.errorHandling = c.ErrorHandling
return b, nil
}
// Run starts the event loop that pushes Prometheus metrics to Graphite at the
// configured interval.
func (b *Bridge) Run(ctx context.Context) {
ticker := time.NewTicker(b.interval)
defer ticker.Stop()
for {
select {
case <-ticker.C:
if err := b.Push(); err != nil && b.logger != nil {
b.logger.Println("error pushing to Graphite:", err)
}
case <-ctx.Done():
return
}
}
}
// Push pushes Prometheus metrics to the configured Graphite server.
func (b *Bridge) Push() error {
mfs, err := b.g.Gather()
if err != nil || len(mfs) == 0 {
switch b.errorHandling {
case AbortOnError:
return err
case ContinueOnError:
if b.logger != nil {
b.logger.Println("continue on error:", err)
}
default:
panic("unrecognized error handling value")
}
}
conn, err := net.DialTimeout("tcp", b.url, b.timeout)
if err != nil {
return err
}
defer conn.Close()
return writeMetrics(conn, mfs, b.prefix, model.Now())
}
func writeMetrics(w io.Writer, mfs []*dto.MetricFamily, prefix string, now model.Time) error {
vec, err := expfmt.ExtractSamples(&expfmt.DecodeOptions{
Timestamp: now,
}, mfs...)
if err != nil {
return err
}
buf := bufio.NewWriter(w)
for _, s := range vec {
if err := writeSanitized(buf, prefix); err != nil {
return err
}
if err := buf.WriteByte('.'); err != nil {
return err
}
if err := writeMetric(buf, s.Metric); err != nil {
return err
}
if _, err := fmt.Fprintf(buf, " %g %d\n", s.Value, int64(s.Timestamp)/millisecondsPerSecond); err != nil {
return err
}
if err := buf.Flush(); err != nil {
return err
}
}
return nil
}
func writeMetric(buf *bufio.Writer, m model.Metric) error {
metricName, hasName := m[model.MetricNameLabel]
numLabels := len(m) - 1
if !hasName {
numLabels = len(m)
}
labelStrings := make([]string, 0, numLabels)
for label, value := range m {
if label != model.MetricNameLabel {
labelStrings = append(labelStrings, fmt.Sprintf("%s %s", string(label), string(value)))
}
}
var err error
switch numLabels {
case 0:
if hasName {
return writeSanitized(buf, string(metricName))
}
default:
sort.Strings(labelStrings)
if err = writeSanitized(buf, string(metricName)); err != nil {
return err
}
for _, s := range labelStrings {
if err = buf.WriteByte('.'); err != nil {
return err
}
if err = writeSanitized(buf, s); err != nil {
return err
}
}
}
return nil
}
func writeSanitized(buf *bufio.Writer, s string) error {
prevUnderscore := false
for _, c := range s {
c = replaceInvalidRune(c)
if c == '_' {
if prevUnderscore {
continue
}
prevUnderscore = true
} else {
prevUnderscore = false
}
if _, err := buf.WriteRune(c); err != nil {
return err
}
}
return nil
}
func replaceInvalidRune(c rune) rune {
if c == ' ' {
return '.'
}
if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_' || c == ':' || (c >= '0' && c <= '9')) {
return '_'
}
return c
}

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@ -0,0 +1,309 @@
package graphite
import (
"bufio"
"bytes"
"io"
"log"
"net"
"os"
"regexp"
"testing"
"time"
"github.com/prometheus/common/model"
"golang.org/x/net/context"
"github.com/prometheus/client_golang/prometheus"
)
func TestSanitize(t *testing.T) {
testCases := []struct {
in, out string
}{
{in: "hello", out: "hello"},
{in: "hE/l1o", out: "hE_l1o"},
{in: "he,*ll(.o", out: "he_ll_o"},
{in: "hello_there%^&", out: "hello_there_"},
}
var buf bytes.Buffer
w := bufio.NewWriter(&buf)
for i, tc := range testCases {
if err := writeSanitized(w, tc.in); err != nil {
t.Fatalf("write failed: %v", err)
}
if err := w.Flush(); err != nil {
t.Fatalf("flush failed: %v", err)
}
if want, got := tc.out, buf.String(); want != got {
t.Fatalf("test case index %d: got sanitized string %s, want %s", i, got, want)
}
buf.Reset()
}
}
func TestWriteSummary(t *testing.T) {
sumVec := prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "name",
Help: "docstring",
ConstLabels: prometheus.Labels{"constname": "constvalue"},
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"labelname"},
)
sumVec.WithLabelValues("val1").Observe(float64(10))
sumVec.WithLabelValues("val1").Observe(float64(20))
sumVec.WithLabelValues("val1").Observe(float64(30))
sumVec.WithLabelValues("val2").Observe(float64(20))
sumVec.WithLabelValues("val2").Observe(float64(30))
sumVec.WithLabelValues("val2").Observe(float64(40))
reg := prometheus.NewRegistry()
reg.MustRegister(sumVec)
mfs, err := reg.Gather()
if err != nil {
t.Fatalf("error: %v", err)
}
now := model.Time(1477043083)
var buf bytes.Buffer
err = writeMetrics(&buf, mfs, "prefix", now)
if err != nil {
t.Fatalf("error: %v", err)
}
want := `prefix.name.constname.constvalue.labelname.val1.quantile.0_5 20 1477043
prefix.name.constname.constvalue.labelname.val1.quantile.0_9 30 1477043
prefix.name.constname.constvalue.labelname.val1.quantile.0_99 30 1477043
prefix.name_sum.constname.constvalue.labelname.val1 60 1477043
prefix.name_count.constname.constvalue.labelname.val1 3 1477043
prefix.name.constname.constvalue.labelname.val2.quantile.0_5 30 1477043
prefix.name.constname.constvalue.labelname.val2.quantile.0_9 40 1477043
prefix.name.constname.constvalue.labelname.val2.quantile.0_99 40 1477043
prefix.name_sum.constname.constvalue.labelname.val2 90 1477043
prefix.name_count.constname.constvalue.labelname.val2 3 1477043
`
if got := buf.String(); want != got {
t.Fatalf("wanted \n%s\n, got \n%s\n", want, got)
}
}
func TestWriteHistogram(t *testing.T) {
histVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "name",
Help: "docstring",
ConstLabels: prometheus.Labels{"constname": "constvalue"},
Buckets: []float64{0.01, 0.02, 0.05, 0.1},
},
[]string{"labelname"},
)
histVec.WithLabelValues("val1").Observe(float64(10))
histVec.WithLabelValues("val1").Observe(float64(20))
histVec.WithLabelValues("val1").Observe(float64(30))
histVec.WithLabelValues("val2").Observe(float64(20))
histVec.WithLabelValues("val2").Observe(float64(30))
histVec.WithLabelValues("val2").Observe(float64(40))
reg := prometheus.NewRegistry()
reg.MustRegister(histVec)
mfs, err := reg.Gather()
if err != nil {
t.Fatalf("error: %v", err)
}
now := model.Time(1477043083)
var buf bytes.Buffer
err = writeMetrics(&buf, mfs, "prefix", now)
if err != nil {
t.Fatalf("error: %v", err)
}
want := `prefix.name_bucket.constname.constvalue.labelname.val1.le.0_01 0 1477043
prefix.name_bucket.constname.constvalue.labelname.val1.le.0_02 0 1477043
prefix.name_bucket.constname.constvalue.labelname.val1.le.0_05 0 1477043
prefix.name_bucket.constname.constvalue.labelname.val1.le.0_1 0 1477043
prefix.name_sum.constname.constvalue.labelname.val1 60 1477043
prefix.name_count.constname.constvalue.labelname.val1 3 1477043
prefix.name_bucket.constname.constvalue.labelname.val1.le._Inf 3 1477043
prefix.name_bucket.constname.constvalue.labelname.val2.le.0_01 0 1477043
prefix.name_bucket.constname.constvalue.labelname.val2.le.0_02 0 1477043
prefix.name_bucket.constname.constvalue.labelname.val2.le.0_05 0 1477043
prefix.name_bucket.constname.constvalue.labelname.val2.le.0_1 0 1477043
prefix.name_sum.constname.constvalue.labelname.val2 90 1477043
prefix.name_count.constname.constvalue.labelname.val2 3 1477043
prefix.name_bucket.constname.constvalue.labelname.val2.le._Inf 3 1477043
`
if got := buf.String(); want != got {
t.Fatalf("wanted \n%s\n, got \n%s\n", want, got)
}
}
func TestToReader(t *testing.T) {
cntVec := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "name",
Help: "docstring",
ConstLabels: prometheus.Labels{"constname": "constvalue"},
},
[]string{"labelname"},
)
cntVec.WithLabelValues("val1").Inc()
cntVec.WithLabelValues("val2").Inc()
reg := prometheus.NewRegistry()
reg.MustRegister(cntVec)
want := `prefix.name.constname.constvalue.labelname.val1 1 1477043
prefix.name.constname.constvalue.labelname.val2 1 1477043
`
mfs, err := reg.Gather()
if err != nil {
t.Fatalf("error: %v", err)
}
now := model.Time(1477043083)
var buf bytes.Buffer
err = writeMetrics(&buf, mfs, "prefix", now)
if err != nil {
t.Fatalf("error: %v", err)
}
if got := buf.String(); want != got {
t.Fatalf("wanted \n%s\n, got \n%s\n", want, got)
}
}
func TestPush(t *testing.T) {
reg := prometheus.NewRegistry()
cntVec := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "name",
Help: "docstring",
ConstLabels: prometheus.Labels{"constname": "constvalue"},
},
[]string{"labelname"},
)
cntVec.WithLabelValues("val1").Inc()
cntVec.WithLabelValues("val2").Inc()
reg.MustRegister(cntVec)
host := "localhost"
port := ":56789"
b, err := NewBridge(&Config{
URL: host + port,
Gatherer: reg,
Prefix: "prefix",
})
if err != nil {
t.Fatalf("error creating bridge: %v", err)
}
nmg, err := newMockGraphite(port)
if err != nil {
t.Fatalf("error creating mock graphite: %v", err)
}
defer nmg.Close()
err = b.Push()
if err != nil {
t.Fatalf("error pushing: %v", err)
}
wants := []string{
"prefix.name.constname.constvalue.labelname.val1 1",
"prefix.name.constname.constvalue.labelname.val2 1",
}
select {
case got := <-nmg.readc:
for _, want := range wants {
matched, err := regexp.MatchString(want, got)
if err != nil {
t.Fatalf("error pushing: %v", err)
}
if !matched {
t.Fatalf("missing metric:\nno match for %s received by server:\n%s", want, got)
}
}
return
case err := <-nmg.errc:
t.Fatalf("error reading push: %v", err)
case <-time.After(50 * time.Millisecond):
t.Fatalf("no result from graphite server")
}
}
func newMockGraphite(port string) (*mockGraphite, error) {
readc := make(chan string)
errc := make(chan error)
ln, err := net.Listen("tcp", port)
if err != nil {
return nil, err
}
go func() {
conn, err := ln.Accept()
if err != nil {
errc <- err
}
var b bytes.Buffer
io.Copy(&b, conn)
readc <- b.String()
}()
return &mockGraphite{
readc: readc,
errc: errc,
Listener: ln,
}, nil
}
type mockGraphite struct {
readc chan string
errc chan error
net.Listener
}
func ExampleBridge() {
b, err := NewBridge(&Config{
URL: "graphite.example.org:3099",
Gatherer: prometheus.DefaultGatherer,
Prefix: "prefix",
Interval: 15 * time.Second,
Timeout: 10 * time.Second,
ErrorHandling: AbortOnError,
Logger: log.New(os.Stdout, "graphite bridge: ", log.Lshortfile),
})
if err != nil {
panic(err)
}
go func() {
// Start something in a goroutine that uses metrics.
}()
// Push initial metrics to Graphite. Fail fast if the push fails.
if err := b.Push(); err != nil {
panic(err)
}
// Create a Context to control stopping the Run() loop that pushes
// metrics to Graphite.
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
// Start pushing metrics to Graphite in the Run() loop.
b.Run(ctx)
}

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@ -0,0 +1,505 @@
// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"math"
"sort"
"sync/atomic"
"github.com/golang/protobuf/proto"
dto "github.com/prometheus/client_model/go"
)
// A Histogram counts individual observations from an event or sample stream in
// configurable buckets. Similar to a summary, it also provides a sum of
// observations and an observation count.
//
// On the Prometheus server, quantiles can be calculated from a Histogram using
// the histogram_quantile function in the query language.
//
// Note that Histograms, in contrast to Summaries, can be aggregated with the
// Prometheus query language (see the documentation for detailed
// procedures). However, Histograms require the user to pre-define suitable
// buckets, and they are in general less accurate. The Observe method of a
// Histogram has a very low performance overhead in comparison with the Observe
// method of a Summary.
//
// To create Histogram instances, use NewHistogram.
type Histogram interface {
Metric
Collector
// Observe adds a single observation to the histogram.
Observe(float64)
}
// bucketLabel is used for the label that defines the upper bound of a
// bucket of a histogram ("le" -> "less or equal").
const bucketLabel = "le"
// DefBuckets are the default Histogram buckets. The default buckets are
// tailored to broadly measure the response time (in seconds) of a network
// service. Most likely, however, you will be required to define buckets
// customized to your use case.
var (
DefBuckets = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10}
errBucketLabelNotAllowed = fmt.Errorf(
"%q is not allowed as label name in histograms", bucketLabel,
)
)
// LinearBuckets creates 'count' buckets, each 'width' wide, where the lowest
// bucket has an upper bound of 'start'. The final +Inf bucket is not counted
// and not included in the returned slice. The returned slice is meant to be
// used for the Buckets field of HistogramOpts.
//
// The function panics if 'count' is zero or negative.
func LinearBuckets(start, width float64, count int) []float64 {
if count < 1 {
panic("LinearBuckets needs a positive count")
}
buckets := make([]float64, count)
for i := range buckets {
buckets[i] = start
start += width
}
return buckets
}
// ExponentialBuckets creates 'count' buckets, where the lowest bucket has an
// upper bound of 'start' and each following bucket's upper bound is 'factor'
// times the previous bucket's upper bound. The final +Inf bucket is not counted
// and not included in the returned slice. The returned slice is meant to be
// used for the Buckets field of HistogramOpts.
//
// The function panics if 'count' is 0 or negative, if 'start' is 0 or negative,
// or if 'factor' is less than or equal 1.
func ExponentialBuckets(start, factor float64, count int) []float64 {
if count < 1 {
panic("ExponentialBuckets needs a positive count")
}
if start <= 0 {
panic("ExponentialBuckets needs a positive start value")
}
if factor <= 1 {
panic("ExponentialBuckets needs a factor greater than 1")
}
buckets := make([]float64, count)
for i := range buckets {
buckets[i] = start
start *= factor
}
return buckets
}
// HistogramOpts bundles the options for creating a Histogram metric. It is
// mandatory to set Name and Help to a non-empty string. All other fields are
// optional and can safely be left at their zero value.
type HistogramOpts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Histogram (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the Histogram must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this Histogram. Mandatory!
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this metric. Metrics
// with the same fully-qualified name must have the same label names in
// their ConstLabels.
//
// ConstLabels are only used rarely. In particular, do not use them to
// attach the same labels to all your metrics. Those use cases are
// better covered by target labels set by the scraping Prometheus
// server, or by one specific metric (e.g. a build_info or a
// machine_role metric). See also
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
ConstLabels Labels
// Buckets defines the buckets into which observations are counted. Each
// element in the slice is the upper inclusive bound of a bucket. The
// values must be sorted in strictly increasing order. There is no need
// to add a highest bucket with +Inf bound, it will be added
// implicitly. The default value is DefBuckets.
Buckets []float64
}
// NewHistogram creates a new Histogram based on the provided HistogramOpts. It
// panics if the buckets in HistogramOpts are not in strictly increasing order.
func NewHistogram(opts HistogramOpts) Histogram {
return newHistogram(
NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
),
opts,
)
}
func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram {
if len(desc.variableLabels) != len(labelValues) {
panic(errInconsistentCardinality)
}
for _, n := range desc.variableLabels {
if n == bucketLabel {
panic(errBucketLabelNotAllowed)
}
}
for _, lp := range desc.constLabelPairs {
if lp.GetName() == bucketLabel {
panic(errBucketLabelNotAllowed)
}
}
if len(opts.Buckets) == 0 {
opts.Buckets = DefBuckets
}
h := &histogram{
desc: desc,
upperBounds: opts.Buckets,
labelPairs: makeLabelPairs(desc, labelValues),
}
for i, upperBound := range h.upperBounds {
if i < len(h.upperBounds)-1 {
if upperBound >= h.upperBounds[i+1] {
panic(fmt.Errorf(
"histogram buckets must be in increasing order: %f >= %f",
upperBound, h.upperBounds[i+1],
))
}
} else {
if math.IsInf(upperBound, +1) {
// The +Inf bucket is implicit. Remove it here.
h.upperBounds = h.upperBounds[:i]
}
}
}
// Finally we know the final length of h.upperBounds and can make counts.
h.counts = make([]uint64, len(h.upperBounds))
h.init(h) // Init self-collection.
return h
}
type histogram struct {
// sumBits contains the bits of the float64 representing the sum of all
// observations. sumBits and count have to go first in the struct to
// guarantee alignment for atomic operations.
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
sumBits uint64
count uint64
selfCollector
// Note that there is no mutex required.
desc *Desc
upperBounds []float64
counts []uint64
labelPairs []*dto.LabelPair
}
func (h *histogram) Desc() *Desc {
return h.desc
}
func (h *histogram) Observe(v float64) {
// TODO(beorn7): For small numbers of buckets (<30), a linear search is
// slightly faster than the binary search. If we really care, we could
// switch from one search strategy to the other depending on the number
// of buckets.
//
// Microbenchmarks (BenchmarkHistogramNoLabels):
// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
i := sort.SearchFloat64s(h.upperBounds, v)
if i < len(h.counts) {
atomic.AddUint64(&h.counts[i], 1)
}
atomic.AddUint64(&h.count, 1)
for {
oldBits := atomic.LoadUint64(&h.sumBits)
newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
if atomic.CompareAndSwapUint64(&h.sumBits, oldBits, newBits) {
break
}
}
}
func (h *histogram) Write(out *dto.Metric) error {
his := &dto.Histogram{}
buckets := make([]*dto.Bucket, len(h.upperBounds))
his.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&h.sumBits)))
his.SampleCount = proto.Uint64(atomic.LoadUint64(&h.count))
var count uint64
for i, upperBound := range h.upperBounds {
count += atomic.LoadUint64(&h.counts[i])
buckets[i] = &dto.Bucket{
CumulativeCount: proto.Uint64(count),
UpperBound: proto.Float64(upperBound),
}
}
his.Bucket = buckets
out.Histogram = his
out.Label = h.labelPairs
return nil
}
// HistogramVec is a Collector that bundles a set of Histograms that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. HTTP request latencies, partitioned by status code and method). Create
// instances with NewHistogramVec.
type HistogramVec struct {
*metricVec
}
// NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
// partitioned by the given label names.
func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &HistogramVec{
metricVec: newMetricVec(desc, func(lvs ...string) Metric {
return newHistogram(desc, opts, lvs...)
}),
}
}
// GetMetricWithLabelValues returns the Histogram for the given slice of label
// values (same order as the VariableLabels in Desc). If that combination of
// label values is accessed for the first time, a new Histogram is created.
//
// It is possible to call this method without using the returned Histogram to only
// create the new Histogram but leave it at its starting value, a Histogram without
// any observations.
//
// Keeping the Histogram for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Histogram from the HistogramVec. In that case, the
// Histogram will still exist, but it will not be exported anymore, even if a
// Histogram with the same label values is created later. See also the CounterVec
// example.
//
// An error is returned if the number of label values is not the same as the
// number of VariableLabels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the GaugeVec example.
func (v *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Observer), err
}
return nil, err
}
// GetMetricWith returns the Histogram for the given Labels map (the label names
// must match those of the VariableLabels in Desc). If that label map is
// accessed for the first time, a new Histogram is created. Implications of
// creating a Histogram without using it and keeping the Histogram for later use
// are the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *HistogramVec) GetMetricWith(labels Labels) (Observer, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Observer), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
// myVec.WithLabelValues("404", "GET").Observe(42.21)
func (v *HistogramVec) WithLabelValues(lvs ...string) Observer {
h, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return h
}
// With works as GetMetricWith but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
func (v *HistogramVec) With(labels Labels) Observer {
h, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return h
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the HistogramVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *HistogramVec) CurryWith(labels Labels) (ObserverVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &HistogramVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *HistogramVec) MustCurryWith(labels Labels) ObserverVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
type constHistogram struct {
desc *Desc
count uint64
sum float64
buckets map[float64]uint64
labelPairs []*dto.LabelPair
}
func (h *constHistogram) Desc() *Desc {
return h.desc
}
func (h *constHistogram) Write(out *dto.Metric) error {
his := &dto.Histogram{}
buckets := make([]*dto.Bucket, 0, len(h.buckets))
his.SampleCount = proto.Uint64(h.count)
his.SampleSum = proto.Float64(h.sum)
for upperBound, count := range h.buckets {
buckets = append(buckets, &dto.Bucket{
CumulativeCount: proto.Uint64(count),
UpperBound: proto.Float64(upperBound),
})
}
if len(buckets) > 0 {
sort.Sort(buckSort(buckets))
}
his.Bucket = buckets
out.Histogram = his
out.Label = h.labelPairs
return nil
}
// NewConstHistogram returns a metric representing a Prometheus histogram with
// fixed values for the count, sum, and bucket counts. As those parameters
// cannot be changed, the returned value does not implement the Histogram
// interface (but only the Metric interface). Users of this package will not
// have much use for it in regular operations. However, when implementing custom
// Collectors, it is useful as a throw-away metric that is generated on the fly
// to send it to Prometheus in the Collect method.
//
// buckets is a map of upper bounds to cumulative counts, excluding the +Inf
// bucket.
//
// NewConstHistogram returns an error if the length of labelValues is not
// consistent with the variable labels in Desc.
func NewConstHistogram(
desc *Desc,
count uint64,
sum float64,
buckets map[float64]uint64,
labelValues ...string,
) (Metric, error) {
if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
return nil, err
}
return &constHistogram{
desc: desc,
count: count,
sum: sum,
buckets: buckets,
labelPairs: makeLabelPairs(desc, labelValues),
}, nil
}
// MustNewConstHistogram is a version of NewConstHistogram that panics where
// NewConstMetric would have returned an error.
func MustNewConstHistogram(
desc *Desc,
count uint64,
sum float64,
buckets map[float64]uint64,
labelValues ...string,
) Metric {
m, err := NewConstHistogram(desc, count, sum, buckets, labelValues...)
if err != nil {
panic(err)
}
return m
}
type buckSort []*dto.Bucket
func (s buckSort) Len() int {
return len(s)
}
func (s buckSort) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s buckSort) Less(i, j int) bool {
return s[i].GetUpperBound() < s[j].GetUpperBound()
}

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@ -0,0 +1,348 @@
// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"math"
"math/rand"
"reflect"
"sort"
"sync"
"testing"
"testing/quick"
dto "github.com/prometheus/client_model/go"
)
func benchmarkHistogramObserve(w int, b *testing.B) {
b.StopTimer()
wg := new(sync.WaitGroup)
wg.Add(w)
g := new(sync.WaitGroup)
g.Add(1)
s := NewHistogram(HistogramOpts{})
for i := 0; i < w; i++ {
go func() {
g.Wait()
for i := 0; i < b.N; i++ {
s.Observe(float64(i))
}
wg.Done()
}()
}
b.StartTimer()
g.Done()
wg.Wait()
}
func BenchmarkHistogramObserve1(b *testing.B) {
benchmarkHistogramObserve(1, b)
}
func BenchmarkHistogramObserve2(b *testing.B) {
benchmarkHistogramObserve(2, b)
}
func BenchmarkHistogramObserve4(b *testing.B) {
benchmarkHistogramObserve(4, b)
}
func BenchmarkHistogramObserve8(b *testing.B) {
benchmarkHistogramObserve(8, b)
}
func benchmarkHistogramWrite(w int, b *testing.B) {
b.StopTimer()
wg := new(sync.WaitGroup)
wg.Add(w)
g := new(sync.WaitGroup)
g.Add(1)
s := NewHistogram(HistogramOpts{})
for i := 0; i < 1000000; i++ {
s.Observe(float64(i))
}
for j := 0; j < w; j++ {
outs := make([]dto.Metric, b.N)
go func(o []dto.Metric) {
g.Wait()
for i := 0; i < b.N; i++ {
s.Write(&o[i])
}
wg.Done()
}(outs)
}
b.StartTimer()
g.Done()
wg.Wait()
}
func BenchmarkHistogramWrite1(b *testing.B) {
benchmarkHistogramWrite(1, b)
}
func BenchmarkHistogramWrite2(b *testing.B) {
benchmarkHistogramWrite(2, b)
}
func BenchmarkHistogramWrite4(b *testing.B) {
benchmarkHistogramWrite(4, b)
}
func BenchmarkHistogramWrite8(b *testing.B) {
benchmarkHistogramWrite(8, b)
}
func TestHistogramNonMonotonicBuckets(t *testing.T) {
testCases := map[string][]float64{
"not strictly monotonic": {1, 2, 2, 3},
"not monotonic at all": {1, 2, 4, 3, 5},
"have +Inf in the middle": {1, 2, math.Inf(+1), 3},
}
for name, buckets := range testCases {
func() {
defer func() {
if r := recover(); r == nil {
t.Errorf("Buckets %v are %s but NewHistogram did not panic.", buckets, name)
}
}()
_ = NewHistogram(HistogramOpts{
Name: "test_histogram",
Help: "helpless",
Buckets: buckets,
})
}()
}
}
// Intentionally adding +Inf here to test if that case is handled correctly.
// Also, getCumulativeCounts depends on it.
var testBuckets = []float64{-2, -1, -0.5, 0, 0.5, 1, 2, math.Inf(+1)}
func TestHistogramConcurrency(t *testing.T) {
if testing.Short() {
t.Skip("Skipping test in short mode.")
}
rand.Seed(42)
it := func(n uint32) bool {
mutations := int(n%1e4 + 1e4)
concLevel := int(n%5 + 1)
total := mutations * concLevel
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
sum := NewHistogram(HistogramOpts{
Name: "test_histogram",
Help: "helpless",
Buckets: testBuckets,
})
allVars := make([]float64, total)
var sampleSum float64
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
for j := 0; j < mutations; j++ {
v := rand.NormFloat64()
vals[j] = v
allVars[i*mutations+j] = v
sampleSum += v
}
go func(vals []float64) {
start.Wait()
for _, v := range vals {
sum.Observe(v)
}
end.Done()
}(vals)
}
sort.Float64s(allVars)
start.Done()
end.Wait()
m := &dto.Metric{}
sum.Write(m)
if got, want := int(*m.Histogram.SampleCount), total; got != want {
t.Errorf("got sample count %d, want %d", got, want)
}
if got, want := *m.Histogram.SampleSum, sampleSum; math.Abs((got-want)/want) > 0.001 {
t.Errorf("got sample sum %f, want %f", got, want)
}
wantCounts := getCumulativeCounts(allVars)
if got, want := len(m.Histogram.Bucket), len(testBuckets)-1; got != want {
t.Errorf("got %d buckets in protobuf, want %d", got, want)
}
for i, wantBound := range testBuckets {
if i == len(testBuckets)-1 {
break // No +Inf bucket in protobuf.
}
if gotBound := *m.Histogram.Bucket[i].UpperBound; gotBound != wantBound {
t.Errorf("got bound %f, want %f", gotBound, wantBound)
}
if gotCount, wantCount := *m.Histogram.Bucket[i].CumulativeCount, wantCounts[i]; gotCount != wantCount {
t.Errorf("got count %d, want %d", gotCount, wantCount)
}
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Error(err)
}
}
func TestHistogramVecConcurrency(t *testing.T) {
if testing.Short() {
t.Skip("Skipping test in short mode.")
}
rand.Seed(42)
objectives := make([]float64, 0, len(DefObjectives))
for qu := range DefObjectives {
objectives = append(objectives, qu)
}
sort.Float64s(objectives)
it := func(n uint32) bool {
mutations := int(n%1e4 + 1e4)
concLevel := int(n%7 + 1)
vecLength := int(n%3 + 1)
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
his := NewHistogramVec(
HistogramOpts{
Name: "test_histogram",
Help: "helpless",
Buckets: []float64{-2, -1, -0.5, 0, 0.5, 1, 2, math.Inf(+1)},
},
[]string{"label"},
)
allVars := make([][]float64, vecLength)
sampleSums := make([]float64, vecLength)
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
picks := make([]int, mutations)
for j := 0; j < mutations; j++ {
v := rand.NormFloat64()
vals[j] = v
pick := rand.Intn(vecLength)
picks[j] = pick
allVars[pick] = append(allVars[pick], v)
sampleSums[pick] += v
}
go func(vals []float64) {
start.Wait()
for i, v := range vals {
his.WithLabelValues(string('A' + picks[i])).Observe(v)
}
end.Done()
}(vals)
}
for _, vars := range allVars {
sort.Float64s(vars)
}
start.Done()
end.Wait()
for i := 0; i < vecLength; i++ {
m := &dto.Metric{}
s := his.WithLabelValues(string('A' + i))
s.(Histogram).Write(m)
if got, want := len(m.Histogram.Bucket), len(testBuckets)-1; got != want {
t.Errorf("got %d buckets in protobuf, want %d", got, want)
}
if got, want := int(*m.Histogram.SampleCount), len(allVars[i]); got != want {
t.Errorf("got sample count %d, want %d", got, want)
}
if got, want := *m.Histogram.SampleSum, sampleSums[i]; math.Abs((got-want)/want) > 0.001 {
t.Errorf("got sample sum %f, want %f", got, want)
}
wantCounts := getCumulativeCounts(allVars[i])
for j, wantBound := range testBuckets {
if j == len(testBuckets)-1 {
break // No +Inf bucket in protobuf.
}
if gotBound := *m.Histogram.Bucket[j].UpperBound; gotBound != wantBound {
t.Errorf("got bound %f, want %f", gotBound, wantBound)
}
if gotCount, wantCount := *m.Histogram.Bucket[j].CumulativeCount, wantCounts[j]; gotCount != wantCount {
t.Errorf("got count %d, want %d", gotCount, wantCount)
}
}
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Error(err)
}
}
func getCumulativeCounts(vars []float64) []uint64 {
counts := make([]uint64, len(testBuckets))
for _, v := range vars {
for i := len(testBuckets) - 1; i >= 0; i-- {
if v > testBuckets[i] {
break
}
counts[i]++
}
}
return counts
}
func TestBuckets(t *testing.T) {
got := LinearBuckets(-15, 5, 6)
want := []float64{-15, -10, -5, 0, 5, 10}
if !reflect.DeepEqual(got, want) {
t.Errorf("linear buckets: got %v, want %v", got, want)
}
got = ExponentialBuckets(100, 1.2, 3)
want = []float64{100, 120, 144}
if !reflect.DeepEqual(got, want) {
t.Errorf("linear buckets: got %v, want %v", got, want)
}
}

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@ -0,0 +1,512 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"bufio"
"bytes"
"compress/gzip"
"fmt"
"io"
"net"
"net/http"
"strconv"
"strings"
"sync"
"time"
"github.com/prometheus/common/expfmt"
)
// TODO(beorn7): Remove this whole file. It is a partial mirror of
// promhttp/http.go (to avoid circular import chains) where everything HTTP
// related should live. The functions here are just for avoiding
// breakage. Everything is deprecated.
const (
contentTypeHeader = "Content-Type"
contentLengthHeader = "Content-Length"
contentEncodingHeader = "Content-Encoding"
acceptEncodingHeader = "Accept-Encoding"
)
var bufPool sync.Pool
func getBuf() *bytes.Buffer {
buf := bufPool.Get()
if buf == nil {
return &bytes.Buffer{}
}
return buf.(*bytes.Buffer)
}
func giveBuf(buf *bytes.Buffer) {
buf.Reset()
bufPool.Put(buf)
}
// Handler returns an HTTP handler for the DefaultGatherer. It is
// already instrumented with InstrumentHandler (using "prometheus" as handler
// name).
//
// Deprecated: Please note the issues described in the doc comment of
// InstrumentHandler. You might want to consider using
// promhttp.InstrumentedHandler instead.
func Handler() http.Handler {
return InstrumentHandler("prometheus", UninstrumentedHandler())
}
// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
//
// Deprecated: Use promhttp.Handler instead. See there for further documentation.
func UninstrumentedHandler() http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
mfs, err := DefaultGatherer.Gather()
if err != nil {
http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
contentType := expfmt.Negotiate(req.Header)
buf := getBuf()
defer giveBuf(buf)
writer, encoding := decorateWriter(req, buf)
enc := expfmt.NewEncoder(writer, contentType)
var lastErr error
for _, mf := range mfs {
if err := enc.Encode(mf); err != nil {
lastErr = err
http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
}
if closer, ok := writer.(io.Closer); ok {
closer.Close()
}
if lastErr != nil && buf.Len() == 0 {
http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
return
}
header := w.Header()
header.Set(contentTypeHeader, string(contentType))
header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
if encoding != "" {
header.Set(contentEncodingHeader, encoding)
}
w.Write(buf.Bytes())
})
}
// decorateWriter wraps a writer to handle gzip compression if requested. It
// returns the decorated writer and the appropriate "Content-Encoding" header
// (which is empty if no compression is enabled).
func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
header := request.Header.Get(acceptEncodingHeader)
parts := strings.Split(header, ",")
for _, part := range parts {
part = strings.TrimSpace(part)
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
return gzip.NewWriter(writer), "gzip"
}
}
return writer, ""
}
var instLabels = []string{"method", "code"}
type nower interface {
Now() time.Time
}
type nowFunc func() time.Time
func (n nowFunc) Now() time.Time {
return n()
}
var now nower = nowFunc(func() time.Time {
return time.Now()
})
// InstrumentHandler wraps the given HTTP handler for instrumentation. It
// registers four metric collectors (if not already done) and reports HTTP
// metrics to the (newly or already) registered collectors: http_requests_total
// (CounterVec), http_request_duration_microseconds (Summary),
// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
// has a constant label named "handler" with the provided handlerName as
// value. http_requests_total is a metric vector partitioned by HTTP method
// (label name "method") and HTTP status code (label name "code").
//
// Deprecated: InstrumentHandler has several issues. Use the tooling provided in
// package promhttp instead. The issues are the following:
//
// - It uses Summaries rather than Histograms. Summaries are not useful if
// aggregation across multiple instances is required.
//
// - It uses microseconds as unit, which is deprecated and should be replaced by
// seconds.
//
// - The size of the request is calculated in a separate goroutine. Since this
// calculator requires access to the request header, it creates a race with
// any writes to the header performed during request handling.
// httputil.ReverseProxy is a prominent example for a handler
// performing such writes.
//
// - It has additional issues with HTTP/2, cf.
// https://github.com/prometheus/client_golang/issues/272.
func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
}
// InstrumentHandlerFunc wraps the given function for instrumentation. It
// otherwise works in the same way as InstrumentHandler (and shares the same
// issues).
//
// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
// InstrumentHandler is. Use the tooling provided in package promhttp instead.
func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
return InstrumentHandlerFuncWithOpts(
SummaryOpts{
Subsystem: "http",
ConstLabels: Labels{"handler": handlerName},
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
handlerFunc,
)
}
// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
// issues) but provides more flexibility (at the cost of a more complex call
// syntax). As InstrumentHandler, this function registers four metric
// collectors, but it uses the provided SummaryOpts to create them. However, the
// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
// by "requests_total", "request_duration_microseconds", "request_size_bytes",
// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
// help string. The names of the variable labels of the http_requests_total
// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
//
// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
// behavior of InstrumentHandler:
//
// prometheus.InstrumentHandlerWithOpts(
// prometheus.SummaryOpts{
// Subsystem: "http",
// ConstLabels: prometheus.Labels{"handler": handlerName},
// },
// handler,
// )
//
// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
// and all its fields are set to the equally named fields in the provided
// SummaryOpts.
//
// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
// InstrumentHandler is. Use the tooling provided in package promhttp instead.
func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
}
// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
// the same issues) but provides more flexibility (at the cost of a more complex
// call syntax). See InstrumentHandlerWithOpts for details how the provided
// SummaryOpts are used.
//
// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
// as InstrumentHandler is. Use the tooling provided in package promhttp instead.
func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
reqCnt := NewCounterVec(
CounterOpts{
Namespace: opts.Namespace,
Subsystem: opts.Subsystem,
Name: "requests_total",
Help: "Total number of HTTP requests made.",
ConstLabels: opts.ConstLabels,
},
instLabels,
)
if err := Register(reqCnt); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
reqCnt = are.ExistingCollector.(*CounterVec)
} else {
panic(err)
}
}
opts.Name = "request_duration_microseconds"
opts.Help = "The HTTP request latencies in microseconds."
reqDur := NewSummary(opts)
if err := Register(reqDur); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
reqDur = are.ExistingCollector.(Summary)
} else {
panic(err)
}
}
opts.Name = "request_size_bytes"
opts.Help = "The HTTP request sizes in bytes."
reqSz := NewSummary(opts)
if err := Register(reqSz); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
reqSz = are.ExistingCollector.(Summary)
} else {
panic(err)
}
}
opts.Name = "response_size_bytes"
opts.Help = "The HTTP response sizes in bytes."
resSz := NewSummary(opts)
if err := Register(resSz); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
resSz = are.ExistingCollector.(Summary)
} else {
panic(err)
}
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
delegate := &responseWriterDelegator{ResponseWriter: w}
out := computeApproximateRequestSize(r)
_, cn := w.(http.CloseNotifier)
_, fl := w.(http.Flusher)
_, hj := w.(http.Hijacker)
_, rf := w.(io.ReaderFrom)
var rw http.ResponseWriter
if cn && fl && hj && rf {
rw = &fancyResponseWriterDelegator{delegate}
} else {
rw = delegate
}
handlerFunc(rw, r)
elapsed := float64(time.Since(now)) / float64(time.Microsecond)
method := sanitizeMethod(r.Method)
code := sanitizeCode(delegate.status)
reqCnt.WithLabelValues(method, code).Inc()
reqDur.Observe(elapsed)
resSz.Observe(float64(delegate.written))
reqSz.Observe(float64(<-out))
})
}
func computeApproximateRequestSize(r *http.Request) <-chan int {
// Get URL length in current go routine for avoiding a race condition.
// HandlerFunc that runs in parallel may modify the URL.
s := 0
if r.URL != nil {
s += len(r.URL.String())
}
out := make(chan int, 1)
go func() {
s += len(r.Method)
s += len(r.Proto)
for name, values := range r.Header {
s += len(name)
for _, value := range values {
s += len(value)
}
}
s += len(r.Host)
// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
if r.ContentLength != -1 {
s += int(r.ContentLength)
}
out <- s
close(out)
}()
return out
}
type responseWriterDelegator struct {
http.ResponseWriter
status int
written int64
wroteHeader bool
}
func (r *responseWriterDelegator) WriteHeader(code int) {
r.status = code
r.wroteHeader = true
r.ResponseWriter.WriteHeader(code)
}
func (r *responseWriterDelegator) Write(b []byte) (int, error) {
if !r.wroteHeader {
r.WriteHeader(http.StatusOK)
}
n, err := r.ResponseWriter.Write(b)
r.written += int64(n)
return n, err
}
type fancyResponseWriterDelegator struct {
*responseWriterDelegator
}
func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
}
func (f *fancyResponseWriterDelegator) Flush() {
f.ResponseWriter.(http.Flusher).Flush()
}
func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return f.ResponseWriter.(http.Hijacker).Hijack()
}
func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
if !f.wroteHeader {
f.WriteHeader(http.StatusOK)
}
n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
f.written += n
return n, err
}
func sanitizeMethod(m string) string {
switch m {
case "GET", "get":
return "get"
case "PUT", "put":
return "put"
case "HEAD", "head":
return "head"
case "POST", "post":
return "post"
case "DELETE", "delete":
return "delete"
case "CONNECT", "connect":
return "connect"
case "OPTIONS", "options":
return "options"
case "NOTIFY", "notify":
return "notify"
default:
return strings.ToLower(m)
}
}
func sanitizeCode(s int) string {
switch s {
case 100:
return "100"
case 101:
return "101"
case 200:
return "200"
case 201:
return "201"
case 202:
return "202"
case 203:
return "203"
case 204:
return "204"
case 205:
return "205"
case 206:
return "206"
case 300:
return "300"
case 301:
return "301"
case 302:
return "302"
case 304:
return "304"
case 305:
return "305"
case 307:
return "307"
case 400:
return "400"
case 401:
return "401"
case 402:
return "402"
case 403:
return "403"
case 404:
return "404"
case 405:
return "405"
case 406:
return "406"
case 407:
return "407"
case 408:
return "408"
case 409:
return "409"
case 410:
return "410"
case 411:
return "411"
case 412:
return "412"
case 413:
return "413"
case 414:
return "414"
case 415:
return "415"
case 416:
return "416"
case 417:
return "417"
case 418:
return "418"
case 500:
return "500"
case 501:
return "501"
case 502:
return "502"
case 503:
return "503"
case 504:
return "504"
case 505:
return "505"
case 428:
return "428"
case 429:
return "429"
case 431:
return "431"
case 511:
return "511"
default:
return strconv.Itoa(s)
}
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"net/http"
"net/http/httptest"
"testing"
"time"
dto "github.com/prometheus/client_model/go"
)
type respBody string
func (b respBody) ServeHTTP(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusTeapot)
w.Write([]byte(b))
}
func nowSeries(t ...time.Time) nower {
return nowFunc(func() time.Time {
defer func() {
t = t[1:]
}()
return t[0]
})
}
func TestInstrumentHandler(t *testing.T) {
defer func(n nower) {
now = n.(nower)
}(now)
instant := time.Now()
end := instant.Add(30 * time.Second)
now = nowSeries(instant, end)
body := respBody("Howdy there!")
hndlr := InstrumentHandler("test-handler", body)
opts := SummaryOpts{
Subsystem: "http",
ConstLabels: Labels{"handler": "test-handler"},
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
}
reqCnt := NewCounterVec(
CounterOpts{
Namespace: opts.Namespace,
Subsystem: opts.Subsystem,
Name: "requests_total",
Help: "Total number of HTTP requests made.",
ConstLabels: opts.ConstLabels,
},
instLabels,
)
err := Register(reqCnt)
if err == nil {
t.Fatal("expected reqCnt to be registered already")
}
if are, ok := err.(AlreadyRegisteredError); ok {
reqCnt = are.ExistingCollector.(*CounterVec)
} else {
t.Fatal("unexpected registration error:", err)
}
opts.Name = "request_duration_microseconds"
opts.Help = "The HTTP request latencies in microseconds."
reqDur := NewSummary(opts)
err = Register(reqDur)
if err == nil {
t.Fatal("expected reqDur to be registered already")
}
if are, ok := err.(AlreadyRegisteredError); ok {
reqDur = are.ExistingCollector.(Summary)
} else {
t.Fatal("unexpected registration error:", err)
}
opts.Name = "request_size_bytes"
opts.Help = "The HTTP request sizes in bytes."
reqSz := NewSummary(opts)
err = Register(reqSz)
if err == nil {
t.Fatal("expected reqSz to be registered already")
}
if _, ok := err.(AlreadyRegisteredError); !ok {
t.Fatal("unexpected registration error:", err)
}
opts.Name = "response_size_bytes"
opts.Help = "The HTTP response sizes in bytes."
resSz := NewSummary(opts)
err = Register(resSz)
if err == nil {
t.Fatal("expected resSz to be registered already")
}
if _, ok := err.(AlreadyRegisteredError); !ok {
t.Fatal("unexpected registration error:", err)
}
reqCnt.Reset()
resp := httptest.NewRecorder()
req := &http.Request{
Method: "GET",
}
hndlr.ServeHTTP(resp, req)
if resp.Code != http.StatusTeapot {
t.Fatalf("expected status %d, got %d", http.StatusTeapot, resp.Code)
}
if resp.Body.String() != "Howdy there!" {
t.Fatalf("expected body %s, got %s", "Howdy there!", resp.Body.String())
}
out := &dto.Metric{}
reqDur.Write(out)
if want, got := "test-handler", out.Label[0].GetValue(); want != got {
t.Errorf("want label value %q in reqDur, got %q", want, got)
}
if want, got := uint64(1), out.Summary.GetSampleCount(); want != got {
t.Errorf("want sample count %d in reqDur, got %d", want, got)
}
out.Reset()
if want, got := 1, len(reqCnt.metricMap.metrics); want != got {
t.Errorf("want %d children in reqCnt, got %d", want, got)
}
cnt, err := reqCnt.GetMetricWithLabelValues("get", "418")
if err != nil {
t.Fatal(err)
}
cnt.Write(out)
if want, got := "418", out.Label[0].GetValue(); want != got {
t.Errorf("want label value %q in reqCnt, got %q", want, got)
}
if want, got := "test-handler", out.Label[1].GetValue(); want != got {
t.Errorf("want label value %q in reqCnt, got %q", want, got)
}
if want, got := "get", out.Label[2].GetValue(); want != got {
t.Errorf("want label value %q in reqCnt, got %q", want, got)
}
if out.Counter == nil {
t.Fatal("expected non-nil counter in reqCnt")
}
if want, got := 1., out.Counter.GetValue(); want != got {
t.Errorf("want reqCnt of %f, got %f", want, got)
}
}

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package prometheus
import (
"errors"
"fmt"
"strings"
"unicode/utf8"
"github.com/prometheus/common/model"
)
// Labels represents a collection of label name -> value mappings. This type is
// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
// metric vector Collectors, e.g.:
// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
//
// The other use-case is the specification of constant label pairs in Opts or to
// create a Desc.
type Labels map[string]string
// reservedLabelPrefix is a prefix which is not legal in user-supplied
// label names.
const reservedLabelPrefix = "__"
var errInconsistentCardinality = errors.New("inconsistent label cardinality")
func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
if len(labels) != expectedNumberOfValues {
return errInconsistentCardinality
}
for name, val := range labels {
if !utf8.ValidString(val) {
return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
}
}
return nil
}
func validateLabelValues(vals []string, expectedNumberOfValues int) error {
if len(vals) != expectedNumberOfValues {
return errInconsistentCardinality
}
for _, val := range vals {
if !utf8.ValidString(val) {
return fmt.Errorf("label value %q is not valid UTF-8", val)
}
}
return nil
}
func checkLabelName(l string) bool {
return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"strings"
dto "github.com/prometheus/client_model/go"
)
const separatorByte byte = 255
// A Metric models a single sample value with its meta data being exported to
// Prometheus. Implementations of Metric in this package are Gauge, Counter,
// Histogram, Summary, and Untyped.
type Metric interface {
// Desc returns the descriptor for the Metric. This method idempotently
// returns the same descriptor throughout the lifetime of the
// Metric. The returned descriptor is immutable by contract. A Metric
// unable to describe itself must return an invalid descriptor (created
// with NewInvalidDesc).
Desc() *Desc
// Write encodes the Metric into a "Metric" Protocol Buffer data
// transmission object.
//
// Metric implementations must observe concurrency safety as reads of
// this metric may occur at any time, and any blocking occurs at the
// expense of total performance of rendering all registered
// metrics. Ideally, Metric implementations should support concurrent
// readers.
//
// While populating dto.Metric, it is the responsibility of the
// implementation to ensure validity of the Metric protobuf (like valid
// UTF-8 strings or syntactically valid metric and label names). It is
// recommended to sort labels lexicographically. (Implementers may find
// LabelPairSorter useful for that.) Callers of Write should still make
// sure of sorting if they depend on it.
Write(*dto.Metric) error
// TODO(beorn7): The original rationale of passing in a pre-allocated
// dto.Metric protobuf to save allocations has disappeared. The
// signature of this method should be changed to "Write() (*dto.Metric,
// error)".
}
// Opts bundles the options for creating most Metric types. Each metric
// implementation XXX has its own XXXOpts type, but in most cases, it is just be
// an alias of this type (which might change when the requirement arises.)
//
// It is mandatory to set Name and Help to a non-empty string. All other fields
// are optional and can safely be left at their zero value.
type Opts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Metric (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the metric must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this metric. Mandatory!
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this metric. Metrics
// with the same fully-qualified name must have the same label names in
// their ConstLabels.
//
// ConstLabels are only used rarely. In particular, do not use them to
// attach the same labels to all your metrics. Those use cases are
// better covered by target labels set by the scraping Prometheus
// server, or by one specific metric (e.g. a build_info or a
// machine_role metric). See also
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
ConstLabels Labels
}
// BuildFQName joins the given three name components by "_". Empty name
// components are ignored. If the name parameter itself is empty, an empty
// string is returned, no matter what. Metric implementations included in this
// library use this function internally to generate the fully-qualified metric
// name from the name component in their Opts. Users of the library will only
// need this function if they implement their own Metric or instantiate a Desc
// (with NewDesc) directly.
func BuildFQName(namespace, subsystem, name string) string {
if name == "" {
return ""
}
switch {
case namespace != "" && subsystem != "":
return strings.Join([]string{namespace, subsystem, name}, "_")
case namespace != "":
return strings.Join([]string{namespace, name}, "_")
case subsystem != "":
return strings.Join([]string{subsystem, name}, "_")
}
return name
}
// LabelPairSorter implements sort.Interface. It is used to sort a slice of
// dto.LabelPair pointers. This is useful for implementing the Write method of
// custom metrics.
type LabelPairSorter []*dto.LabelPair
func (s LabelPairSorter) Len() int {
return len(s)
}
func (s LabelPairSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s LabelPairSorter) Less(i, j int) bool {
return s[i].GetName() < s[j].GetName()
}
type invalidMetric struct {
desc *Desc
err error
}
// NewInvalidMetric returns a metric whose Write method always returns the
// provided error. It is useful if a Collector finds itself unable to collect
// a metric and wishes to report an error to the registry.
func NewInvalidMetric(desc *Desc, err error) Metric {
return &invalidMetric{desc, err}
}
func (m *invalidMetric) Desc() *Desc { return m.desc }
func (m *invalidMetric) Write(*dto.Metric) error { return m.err }

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import "testing"
func TestBuildFQName(t *testing.T) {
scenarios := []struct{ namespace, subsystem, name, result string }{
{"a", "b", "c", "a_b_c"},
{"", "b", "c", "b_c"},
{"a", "", "c", "a_c"},
{"", "", "c", "c"},
{"a", "b", "", ""},
{"a", "", "", ""},
{"", "b", "", ""},
{" ", "", "", ""},
}
for i, s := range scenarios {
if want, got := s.result, BuildFQName(s.namespace, s.subsystem, s.name); want != got {
t.Errorf("%d. want %s, got %s", i, want, got)
}
}
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Observer is the interface that wraps the Observe method, which is used by
// Histogram and Summary to add observations.
type Observer interface {
Observe(float64)
}
// The ObserverFunc type is an adapter to allow the use of ordinary
// functions as Observers. If f is a function with the appropriate
// signature, ObserverFunc(f) is an Observer that calls f.
//
// This adapter is usually used in connection with the Timer type, and there are
// two general use cases:
//
// The most common one is to use a Gauge as the Observer for a Timer.
// See the "Gauge" Timer example.
//
// The more advanced use case is to create a function that dynamically decides
// which Observer to use for observing the duration. See the "Complex" Timer
// example.
type ObserverFunc func(float64)
// Observe calls f(value). It implements Observer.
func (f ObserverFunc) Observe(value float64) {
f(value)
}
// ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`.
type ObserverVec interface {
GetMetricWith(Labels) (Observer, error)
GetMetricWithLabelValues(lvs ...string) (Observer, error)
With(Labels) Observer
WithLabelValues(...string) Observer
CurryWith(Labels) (ObserverVec, error)
MustCurryWith(Labels) ObserverVec
Collector
}

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import "github.com/prometheus/procfs"
type processCollector struct {
collectFn func(chan<- Metric)
pidFn func() (int, error)
cpuTotal *Desc
openFDs, maxFDs *Desc
vsize, rss *Desc
startTime *Desc
}
// NewProcessCollector returns a collector which exports the current state of
// process metrics including CPU, memory and file descriptor usage as well as
// the process start time for the given process ID under the given namespace.
//
// Currently, the collector depends on a Linux-style proc filesystem and
// therefore only exports metrics for Linux.
func NewProcessCollector(pid int, namespace string) Collector {
return NewProcessCollectorPIDFn(
func() (int, error) { return pid, nil },
namespace,
)
}
// NewProcessCollectorPIDFn works like NewProcessCollector but the process ID is
// determined on each collect anew by calling the given pidFn function.
func NewProcessCollectorPIDFn(
pidFn func() (int, error),
namespace string,
) Collector {
ns := ""
if len(namespace) > 0 {
ns = namespace + "_"
}
c := processCollector{
pidFn: pidFn,
collectFn: func(chan<- Metric) {},
cpuTotal: NewDesc(
ns+"process_cpu_seconds_total",
"Total user and system CPU time spent in seconds.",
nil, nil,
),
openFDs: NewDesc(
ns+"process_open_fds",
"Number of open file descriptors.",
nil, nil,
),
maxFDs: NewDesc(
ns+"process_max_fds",
"Maximum number of open file descriptors.",
nil, nil,
),
vsize: NewDesc(
ns+"process_virtual_memory_bytes",
"Virtual memory size in bytes.",
nil, nil,
),
rss: NewDesc(
ns+"process_resident_memory_bytes",
"Resident memory size in bytes.",
nil, nil,
),
startTime: NewDesc(
ns+"process_start_time_seconds",
"Start time of the process since unix epoch in seconds.",
nil, nil,
),
}
// Set up process metric collection if supported by the runtime.
if _, err := procfs.NewStat(); err == nil {
c.collectFn = c.processCollect
}
return &c
}
// Describe returns all descriptions of the collector.
func (c *processCollector) Describe(ch chan<- *Desc) {
ch <- c.cpuTotal
ch <- c.openFDs
ch <- c.maxFDs
ch <- c.vsize
ch <- c.rss
ch <- c.startTime
}
// Collect returns the current state of all metrics of the collector.
func (c *processCollector) Collect(ch chan<- Metric) {
c.collectFn(ch)
}
// TODO(ts): Bring back error reporting by reverting 7faf9e7 as soon as the
// client allows users to configure the error behavior.
func (c *processCollector) processCollect(ch chan<- Metric) {
pid, err := c.pidFn()
if err != nil {
return
}
p, err := procfs.NewProc(pid)
if err != nil {
return
}
if stat, err := p.NewStat(); err == nil {
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
if startTime, err := stat.StartTime(); err == nil {
ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
}
}
if fds, err := p.FileDescriptorsLen(); err == nil {
ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
}
if limits, err := p.NewLimits(); err == nil {
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
}
}

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// +build linux
package prometheus
import (
"bytes"
"os"
"regexp"
"testing"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/procfs"
)
func TestProcessCollector(t *testing.T) {
if _, err := procfs.Self(); err != nil {
t.Skipf("skipping TestProcessCollector, procfs not available: %s", err)
}
registry := NewRegistry()
if err := registry.Register(NewProcessCollector(os.Getpid(), "")); err != nil {
t.Fatal(err)
}
if err := registry.Register(NewProcessCollectorPIDFn(
func() (int, error) { return os.Getpid(), nil }, "foobar"),
); err != nil {
t.Fatal(err)
}
mfs, err := registry.Gather()
if err != nil {
t.Fatal(err)
}
var buf bytes.Buffer
for _, mf := range mfs {
if _, err := expfmt.MetricFamilyToText(&buf, mf); err != nil {
t.Fatal(err)
}
}
for _, re := range []*regexp.Regexp{
regexp.MustCompile("\nprocess_cpu_seconds_total [0-9]"),
regexp.MustCompile("\nprocess_max_fds [1-9]"),
regexp.MustCompile("\nprocess_open_fds [1-9]"),
regexp.MustCompile("\nprocess_virtual_memory_bytes [1-9]"),
regexp.MustCompile("\nprocess_resident_memory_bytes [1-9]"),
regexp.MustCompile("\nprocess_start_time_seconds [0-9.]{10,}"),
regexp.MustCompile("\nfoobar_process_cpu_seconds_total [0-9]"),
regexp.MustCompile("\nfoobar_process_max_fds [1-9]"),
regexp.MustCompile("\nfoobar_process_open_fds [1-9]"),
regexp.MustCompile("\nfoobar_process_virtual_memory_bytes [1-9]"),
regexp.MustCompile("\nfoobar_process_resident_memory_bytes [1-9]"),
regexp.MustCompile("\nfoobar_process_start_time_seconds [0-9.]{10,}"),
} {
if !re.Match(buf.Bytes()) {
t.Errorf("want body to match %s\n%s", re, buf.String())
}
}
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package promauto provides constructors for the usual Prometheus metrics that
// return them already registered with the global registry
// (prometheus.DefaultRegisterer). This allows very compact code, avoiding any
// references to the registry altogether, but all the constructors in this
// package will panic if the registration fails.
//
// The following example is a complete program to create a histogram of normally
// distributed random numbers from the math/rand package:
//
// package main
//
// import (
// "math/rand"
// "net/http"
//
// "github.com/prometheus/client_golang/prometheus"
// "github.com/prometheus/client_golang/prometheus/promauto"
// "github.com/prometheus/client_golang/prometheus/promhttp"
// )
//
// var histogram = promauto.NewHistogram(prometheus.HistogramOpts{
// Name: "random_numbers",
// Help: "A histogram of normally distributed random numbers.",
// Buckets: prometheus.LinearBuckets(-3, .1, 61),
// })
//
// func Random() {
// for {
// histogram.Observe(rand.NormFloat64())
// }
// }
//
// func main() {
// go Random()
// http.Handle("/metrics", promhttp.Handler())
// http.ListenAndServe(":1971", nil)
// }
//
// Prometheus's version of a minimal hello-world program:
//
// package main
//
// import (
// "fmt"
// "net/http"
//
// "github.com/prometheus/client_golang/prometheus"
// "github.com/prometheus/client_golang/prometheus/promauto"
// "github.com/prometheus/client_golang/prometheus/promhttp"
// )
//
// func main() {
// http.Handle("/", promhttp.InstrumentHandlerCounter(
// promauto.NewCounterVec(
// prometheus.CounterOpts{
// Name: "hello_requests_total",
// Help: "Total number of hello-world requests by HTTP code.",
// },
// []string{"code"},
// ),
// http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// fmt.Fprint(w, "Hello, world!")
// }),
// ))
// http.Handle("/metrics", promhttp.Handler())
// http.ListenAndServe(":1971", nil)
// }
//
// This appears very handy. So why are these constructors locked away in a
// separate package? There are two caveats:
//
// First, in more complex programs, global state is often quite problematic.
// That's the reason why the metrics constructors in the prometheus package do
// not interact with the global prometheus.DefaultRegisterer on their own. You
// are free to use the Register or MustRegister functions to register them with
// the global prometheus.DefaultRegisterer, but you could as well choose a local
// Registerer (usually created with prometheus.NewRegistry, but there are other
// scenarios, e.g. testing).
//
// The second issue is that registration may fail, e.g. if a metric inconsistent
// with the newly to be registered one is already registered. But how to signal
// and handle a panic in the automatic registration with the default registry?
// The only way is panicking. While panicking on invalid input provided by the
// programmer is certainly fine, things are a bit more subtle in this case: You
// might just add another package to the program, and that package (in its init
// function) happens to register a metric with the same name as your code. Now,
// all of a sudden, either your code or the code of the newly imported package
// panics, depending on initialization order, without any opportunity to handle
// the case gracefully. Even worse is a scenario where registration happens
// later during the runtime (e.g. upon loading some kind of plugin), where the
// panic could be triggered long after the code has been deployed to
// production. A possibility to panic should be explicitly called out by the
// Must… idiom, cf. prometheus.MustRegister. But adding a separate set of
// constructors in the prometheus package called MustRegisterNewCounterVec or
// similar would be quite unwieldy. Adding an extra MustRegister method to each
// metric, returning the registered metric, would result in nice code for those
// using the method, but would pollute every single metric interface for
// everybody avoiding the global registry.
//
// To address both issues, the problematic auto-registering and possibly
// panicking constructors are all in this package with a clear warning
// ahead. And whoever cares about avoiding global state and possibly panicking
// function calls can simply ignore the existence of the promauto package
// altogether.
//
// A final note: There is a similar case in the net/http package of the standard
// library. It has DefaultServeMux as a global instance of ServeMux, and the
// Handle function acts on it, panicking if a handler for the same pattern has
// already been registered. However, one might argue that the whole HTTP routing
// is usually set up closely together in the same package or file, while
// Prometheus metrics tend to be spread widely over the codebase, increasing the
// chance of surprising registration failures. Furthermore, the use of global
// state in net/http has been criticized widely, and some avoid it altogether.
package promauto
import "github.com/prometheus/client_golang/prometheus"
// NewCounter works like the function of the same name in the prometheus package
// but it automatically registers the Counter with the
// prometheus.DefaultRegisterer. If the registration fails, NewCounter panics.
func NewCounter(opts prometheus.CounterOpts) prometheus.Counter {
c := prometheus.NewCounter(opts)
prometheus.MustRegister(c)
return c
}
// NewCounterVec works like the function of the same name in the prometheus
// package but it automatically registers the CounterVec with the
// prometheus.DefaultRegisterer. If the registration fails, NewCounterVec
// panics.
func NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus.CounterVec {
c := prometheus.NewCounterVec(opts, labelNames)
prometheus.MustRegister(c)
return c
}
// NewCounterFunc works like the function of the same name in the prometheus
// package but it automatically registers the CounterFunc with the
// prometheus.DefaultRegisterer. If the registration fails, NewCounterFunc
// panics.
func NewCounterFunc(opts prometheus.CounterOpts, function func() float64) prometheus.CounterFunc {
g := prometheus.NewCounterFunc(opts, function)
prometheus.MustRegister(g)
return g
}
// NewGauge works like the function of the same name in the prometheus package
// but it automatically registers the Gauge with the
// prometheus.DefaultRegisterer. If the registration fails, NewGauge panics.
func NewGauge(opts prometheus.GaugeOpts) prometheus.Gauge {
g := prometheus.NewGauge(opts)
prometheus.MustRegister(g)
return g
}
// NewGaugeVec works like the function of the same name in the prometheus
// package but it automatically registers the GaugeVec with the
// prometheus.DefaultRegisterer. If the registration fails, NewGaugeVec panics.
func NewGaugeVec(opts prometheus.GaugeOpts, labelNames []string) *prometheus.GaugeVec {
g := prometheus.NewGaugeVec(opts, labelNames)
prometheus.MustRegister(g)
return g
}
// NewGaugeFunc works like the function of the same name in the prometheus
// package but it automatically registers the GaugeFunc with the
// prometheus.DefaultRegisterer. If the registration fails, NewGaugeFunc panics.
func NewGaugeFunc(opts prometheus.GaugeOpts, function func() float64) prometheus.GaugeFunc {
g := prometheus.NewGaugeFunc(opts, function)
prometheus.MustRegister(g)
return g
}
// NewSummary works like the function of the same name in the prometheus package
// but it automatically registers the Summary with the
// prometheus.DefaultRegisterer. If the registration fails, NewSummary panics.
func NewSummary(opts prometheus.SummaryOpts) prometheus.Summary {
s := prometheus.NewSummary(opts)
prometheus.MustRegister(s)
return s
}
// NewSummaryVec works like the function of the same name in the prometheus
// package but it automatically registers the SummaryVec with the
// prometheus.DefaultRegisterer. If the registration fails, NewSummaryVec
// panics.
func NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec {
s := prometheus.NewSummaryVec(opts, labelNames)
prometheus.MustRegister(s)
return s
}
// NewHistogram works like the function of the same name in the prometheus
// package but it automatically registers the Histogram with the
// prometheus.DefaultRegisterer. If the registration fails, NewHistogram panics.
func NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram {
h := prometheus.NewHistogram(opts)
prometheus.MustRegister(h)
return h
}
// NewHistogramVec works like the function of the same name in the prometheus
// package but it automatically registers the HistogramVec with the
// prometheus.DefaultRegisterer. If the registration fails, NewHistogramVec
// panics.
func NewHistogramVec(opts prometheus.HistogramOpts, labelNames []string) *prometheus.HistogramVec {
h := prometheus.NewHistogramVec(opts, labelNames)
prometheus.MustRegister(h)
return h
}

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@ -0,0 +1,199 @@
// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"bufio"
"io"
"net"
"net/http"
)
const (
closeNotifier = 1 << iota
flusher
hijacker
readerFrom
pusher
)
type delegator interface {
http.ResponseWriter
Status() int
Written() int64
}
type responseWriterDelegator struct {
http.ResponseWriter
handler, method string
status int
written int64
wroteHeader bool
observeWriteHeader func(int)
}
func (r *responseWriterDelegator) Status() int {
return r.status
}
func (r *responseWriterDelegator) Written() int64 {
return r.written
}
func (r *responseWriterDelegator) WriteHeader(code int) {
r.status = code
r.wroteHeader = true
r.ResponseWriter.WriteHeader(code)
if r.observeWriteHeader != nil {
r.observeWriteHeader(code)
}
}
func (r *responseWriterDelegator) Write(b []byte) (int, error) {
if !r.wroteHeader {
r.WriteHeader(http.StatusOK)
}
n, err := r.ResponseWriter.Write(b)
r.written += int64(n)
return n, err
}
type closeNotifierDelegator struct{ *responseWriterDelegator }
type flusherDelegator struct{ *responseWriterDelegator }
type hijackerDelegator struct{ *responseWriterDelegator }
type readerFromDelegator struct{ *responseWriterDelegator }
func (d *closeNotifierDelegator) CloseNotify() <-chan bool {
return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
}
func (d *flusherDelegator) Flush() {
d.ResponseWriter.(http.Flusher).Flush()
}
func (d *hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return d.ResponseWriter.(http.Hijacker).Hijack()
}
func (d *readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
if !d.wroteHeader {
d.WriteHeader(http.StatusOK)
}
n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
d.written += n
return n, err
}
var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
func init() {
// TODO(beorn7): Code generation would help here.
pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
return d
}
pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
return &closeNotifierDelegator{d}
}
pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
return &flusherDelegator{d}
}
pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
return struct {
*responseWriterDelegator
http.Flusher
http.CloseNotifier
}{d, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
return &hijackerDelegator{d}
}
pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
return struct {
*responseWriterDelegator
http.Hijacker
http.CloseNotifier
}{d, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
return struct {
*responseWriterDelegator
http.Hijacker
http.Flusher
}{d, &hijackerDelegator{d}, &flusherDelegator{d}}
}
pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
return struct {
*responseWriterDelegator
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
return readerFromDelegator{d}
}
pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
return struct {
*responseWriterDelegator
io.ReaderFrom
http.CloseNotifier
}{d, &readerFromDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Flusher
}{d, &readerFromDelegator{d}, &flusherDelegator{d}}
}
pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Flusher
http.CloseNotifier
}{d, &readerFromDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
}{d, &readerFromDelegator{d}, &hijackerDelegator{d}}
}
pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
http.CloseNotifier
}{d, &readerFromDelegator{d}, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
http.Flusher
}{d, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}}
}
pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.8
package promhttp
import (
"io"
"net/http"
)
type pusherDelegator struct{ *responseWriterDelegator }
func (d *pusherDelegator) Push(target string, opts *http.PushOptions) error {
return d.ResponseWriter.(http.Pusher).Push(target, opts)
}
func init() {
pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
return &pusherDelegator{d}
}
pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
return struct {
*responseWriterDelegator
http.Pusher
http.CloseNotifier
}{d, &pusherDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
return struct {
*responseWriterDelegator
http.Pusher
http.Flusher
}{d, &pusherDelegator{d}, &flusherDelegator{d}}
}
pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
return struct {
*responseWriterDelegator
http.Pusher
http.Flusher
http.CloseNotifier
}{d, &pusherDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
}{d, &pusherDelegator{d}, &hijackerDelegator{d}}
}
pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
http.CloseNotifier
}{d, &pusherDelegator{d}, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
http.Flusher
}{d, &pusherDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}}
}
pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { //23
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, &pusherDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
}{d, &pusherDelegator{d}, &readerFromDelegator{d}}
}
pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.CloseNotifier
}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Flusher
}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &flusherDelegator{d}}
}
pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Flusher
http.CloseNotifier
}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
http.CloseNotifier
}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}, &closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
http.Flusher
}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, &pusherDelegator{d}, &readerFromDelegator{d}, &hijackerDelegator{d}, &flusherDelegator{d}, &closeNotifierDelegator{d}}
}
}
func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
d := &responseWriterDelegator{
ResponseWriter: w,
observeWriteHeader: observeWriteHeaderFunc,
}
id := 0
if _, ok := w.(http.CloseNotifier); ok {
id += closeNotifier
}
if _, ok := w.(http.Flusher); ok {
id += flusher
}
if _, ok := w.(http.Hijacker); ok {
id += hijacker
}
if _, ok := w.(io.ReaderFrom); ok {
id += readerFrom
}
if _, ok := w.(http.Pusher); ok {
id += pusher
}
return pickDelegator[id](d)
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build !go1.8
package promhttp
import (
"io"
"net/http"
)
func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
d := &responseWriterDelegator{
ResponseWriter: w,
observeWriteHeader: observeWriteHeaderFunc,
}
id := 0
if _, ok := w.(http.CloseNotifier); ok {
id += closeNotifier
}
if _, ok := w.(http.Flusher); ok {
id += flusher
}
if _, ok := w.(http.Hijacker); ok {
id += hijacker
}
if _, ok := w.(io.ReaderFrom); ok {
id += readerFrom
}
return pickDelegator[id](d)
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package promhttp provides tooling around HTTP servers and clients.
//
// First, the package allows the creation of http.Handler instances to expose
// Prometheus metrics via HTTP. promhttp.Handler acts on the
// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a
// custom registry or anything that implements the Gatherer interface. It also
// allows the creation of handlers that act differently on errors or allow to
// log errors.
//
// Second, the package provides tooling to instrument instances of http.Handler
// via middleware. Middleware wrappers follow the naming scheme
// InstrumentHandlerX, where X describes the intended use of the middleware.
// See each function's doc comment for specific details.
//
// Finally, the package allows for an http.RoundTripper to be instrumented via
// middleware. Middleware wrappers follow the naming scheme
// InstrumentRoundTripperX, where X describes the intended use of the
// middleware. See each function's doc comment for specific details.
package promhttp
import (
"bytes"
"compress/gzip"
"fmt"
"io"
"net/http"
"strings"
"sync"
"time"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/client_golang/prometheus"
)
const (
contentTypeHeader = "Content-Type"
contentLengthHeader = "Content-Length"
contentEncodingHeader = "Content-Encoding"
acceptEncodingHeader = "Accept-Encoding"
)
var bufPool sync.Pool
func getBuf() *bytes.Buffer {
buf := bufPool.Get()
if buf == nil {
return &bytes.Buffer{}
}
return buf.(*bytes.Buffer)
}
func giveBuf(buf *bytes.Buffer) {
buf.Reset()
bufPool.Put(buf)
}
// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
// default HandlerOpts, i.e. it reports the first error as an HTTP error, it has
// no error logging, and it applies compression if requested by the client.
//
// The returned http.Handler is already instrumented using the
// InstrumentMetricHandler function and the prometheus.DefaultRegisterer. If you
// create multiple http.Handlers by separate calls of the Handler function, the
// metrics used for instrumentation will be shared between them, providing
// global scrape counts.
//
// This function is meant to cover the bulk of basic use cases. If you are doing
// anything that requires more customization (including using a non-default
// Gatherer, different instrumentation, and non-default HandlerOpts), use the
// HandlerFor function. See there for details.
func Handler() http.Handler {
return InstrumentMetricHandler(
prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}),
)
}
// HandlerFor returns an uninstrumented http.Handler for the provided
// Gatherer. The behavior of the Handler is defined by the provided
// HandlerOpts. Thus, HandlerFor is useful to create http.Handlers for custom
// Gatherers, with non-default HandlerOpts, and/or with custom (or no)
// instrumentation. Use the InstrumentMetricHandler function to apply the same
// kind of instrumentation as it is used by the Handler function.
func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
var inFlightSem chan struct{}
if opts.MaxRequestsInFlight > 0 {
inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
}
h := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
if inFlightSem != nil {
select {
case inFlightSem <- struct{}{}: // All good, carry on.
defer func() { <-inFlightSem }()
default:
http.Error(w, fmt.Sprintf(
"Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
), http.StatusServiceUnavailable)
return
}
}
mfs, err := reg.Gather()
if err != nil {
if opts.ErrorLog != nil {
opts.ErrorLog.Println("error gathering metrics:", err)
}
switch opts.ErrorHandling {
case PanicOnError:
panic(err)
case ContinueOnError:
if len(mfs) == 0 {
http.Error(w, "No metrics gathered, last error:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
case HTTPErrorOnError:
http.Error(w, "An error has occurred during metrics gathering:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
}
contentType := expfmt.Negotiate(req.Header)
buf := getBuf()
defer giveBuf(buf)
writer, encoding := decorateWriter(req, buf, opts.DisableCompression)
enc := expfmt.NewEncoder(writer, contentType)
var lastErr error
for _, mf := range mfs {
if err := enc.Encode(mf); err != nil {
lastErr = err
if opts.ErrorLog != nil {
opts.ErrorLog.Println("error encoding metric family:", err)
}
switch opts.ErrorHandling {
case PanicOnError:
panic(err)
case ContinueOnError:
// Handled later.
case HTTPErrorOnError:
http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
}
}
if closer, ok := writer.(io.Closer); ok {
closer.Close()
}
if lastErr != nil && buf.Len() == 0 {
http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
return
}
header := w.Header()
header.Set(contentTypeHeader, string(contentType))
header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
if encoding != "" {
header.Set(contentEncodingHeader, encoding)
}
if _, err := w.Write(buf.Bytes()); err != nil && opts.ErrorLog != nil {
opts.ErrorLog.Println("error while sending encoded metrics:", err)
}
// TODO(beorn7): Consider streaming serving of metrics.
})
if opts.Timeout <= 0 {
return h
}
return http.TimeoutHandler(h, opts.Timeout, fmt.Sprintf(
"Exceeded configured timeout of %v.\n",
opts.Timeout,
))
}
// InstrumentMetricHandler is usually used with an http.Handler returned by the
// HandlerFor function. It instruments the provided http.Handler with two
// metrics: A counter vector "promhttp_metric_handler_requests_total" to count
// scrapes partitioned by HTTP status code, and a gauge
// "promhttp_metric_handler_requests_in_flight" to track the number of
// simultaneous scrapes. This function idempotently registers collectors for
// both metrics with the provided Registerer. It panics if the registration
// fails. The provided metrics are useful to see how many scrapes hit the
// monitored target (which could be from different Prometheus servers or other
// scrapers), and how often they overlap (which would result in more than one
// scrape in flight at the same time). Note that the scrapes-in-flight gauge
// will contain the scrape by which it is exposed, while the scrape counter will
// only get incremented after the scrape is complete (as only then the status
// code is known). For tracking scrape durations, use the
// "scrape_duration_seconds" gauge created by the Prometheus server upon each
// scrape.
func InstrumentMetricHandler(reg prometheus.Registerer, handler http.Handler) http.Handler {
cnt := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "promhttp_metric_handler_requests_total",
Help: "Total number of scrapes by HTTP status code.",
},
[]string{"code"},
)
// Initialize the most likely HTTP status codes.
cnt.WithLabelValues("200")
cnt.WithLabelValues("500")
cnt.WithLabelValues("503")
if err := reg.Register(cnt); err != nil {
if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
cnt = are.ExistingCollector.(*prometheus.CounterVec)
} else {
panic(err)
}
}
gge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "promhttp_metric_handler_requests_in_flight",
Help: "Current number of scrapes being served.",
})
if err := reg.Register(gge); err != nil {
if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
gge = are.ExistingCollector.(prometheus.Gauge)
} else {
panic(err)
}
}
return InstrumentHandlerCounter(cnt, InstrumentHandlerInFlight(gge, handler))
}
// HandlerErrorHandling defines how a Handler serving metrics will handle
// errors.
type HandlerErrorHandling int
// These constants cause handlers serving metrics to behave as described if
// errors are encountered.
const (
// Serve an HTTP status code 500 upon the first error
// encountered. Report the error message in the body.
HTTPErrorOnError HandlerErrorHandling = iota
// Ignore errors and try to serve as many metrics as possible. However,
// if no metrics can be served, serve an HTTP status code 500 and the
// last error message in the body. Only use this in deliberate "best
// effort" metrics collection scenarios. It is recommended to at least
// log errors (by providing an ErrorLog in HandlerOpts) to not mask
// errors completely.
ContinueOnError
// Panic upon the first error encountered (useful for "crash only" apps).
PanicOnError
)
// Logger is the minimal interface HandlerOpts needs for logging. Note that
// log.Logger from the standard library implements this interface, and it is
// easy to implement by custom loggers, if they don't do so already anyway.
type Logger interface {
Println(v ...interface{})
}
// HandlerOpts specifies options how to serve metrics via an http.Handler. The
// zero value of HandlerOpts is a reasonable default.
type HandlerOpts struct {
// ErrorLog specifies an optional logger for errors collecting and
// serving metrics. If nil, errors are not logged at all.
ErrorLog Logger
// ErrorHandling defines how errors are handled. Note that errors are
// logged regardless of the configured ErrorHandling provided ErrorLog
// is not nil.
ErrorHandling HandlerErrorHandling
// If DisableCompression is true, the handler will never compress the
// response, even if requested by the client.
DisableCompression bool
// The number of concurrent HTTP requests is limited to
// MaxRequestsInFlight. Additional requests are responded to with 503
// Service Unavailable and a suitable message in the body. If
// MaxRequestsInFlight is 0 or negative, no limit is applied.
MaxRequestsInFlight int
// If handling a request takes longer than Timeout, it is responded to
// with 503 ServiceUnavailable and a suitable Message. No timeout is
// applied if Timeout is 0 or negative. Note that with the current
// implementation, reaching the timeout simply ends the HTTP requests as
// described above (and even that only if sending of the body hasn't
// started yet), while the bulk work of gathering all the metrics keeps
// running in the background (with the eventual result to be thrown
// away). Until the implementation is improved, it is recommended to
// implement a separate timeout in potentially slow Collectors.
Timeout time.Duration
}
// decorateWriter wraps a writer to handle gzip compression if requested. It
// returns the decorated writer and the appropriate "Content-Encoding" header
// (which is empty if no compression is enabled).
func decorateWriter(request *http.Request, writer io.Writer, compressionDisabled bool) (io.Writer, string) {
if compressionDisabled {
return writer, ""
}
header := request.Header.Get(acceptEncodingHeader)
parts := strings.Split(header, ",")
for _, part := range parts {
part = strings.TrimSpace(part)
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
return gzip.NewWriter(writer), "gzip"
}
}
return writer, ""
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"bytes"
"errors"
"log"
"net/http"
"net/http/httptest"
"strings"
"testing"
"time"
"github.com/prometheus/client_golang/prometheus"
)
type errorCollector struct{}
func (e errorCollector) Describe(ch chan<- *prometheus.Desc) {
ch <- prometheus.NewDesc("invalid_metric", "not helpful", nil, nil)
}
func (e errorCollector) Collect(ch chan<- prometheus.Metric) {
ch <- prometheus.NewInvalidMetric(
prometheus.NewDesc("invalid_metric", "not helpful", nil, nil),
errors.New("collect error"),
)
}
type blockingCollector struct {
CollectStarted, Block chan struct{}
}
func (b blockingCollector) Describe(ch chan<- *prometheus.Desc) {
ch <- prometheus.NewDesc("dummy_desc", "not helpful", nil, nil)
}
func (b blockingCollector) Collect(ch chan<- prometheus.Metric) {
select {
case b.CollectStarted <- struct{}{}:
default:
}
// Collects nothing, just waits for a channel receive.
<-b.Block
}
func TestHandlerErrorHandling(t *testing.T) {
// Create a registry that collects a MetricFamily with two elements,
// another with one, and reports an error.
reg := prometheus.NewRegistry()
cnt := prometheus.NewCounter(prometheus.CounterOpts{
Name: "the_count",
Help: "Ah-ah-ah! Thunder and lightning!",
})
reg.MustRegister(cnt)
cntVec := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "name",
Help: "docstring",
ConstLabels: prometheus.Labels{"constname": "constvalue"},
},
[]string{"labelname"},
)
cntVec.WithLabelValues("val1").Inc()
cntVec.WithLabelValues("val2").Inc()
reg.MustRegister(cntVec)
reg.MustRegister(errorCollector{})
logBuf := &bytes.Buffer{}
logger := log.New(logBuf, "", 0)
writer := httptest.NewRecorder()
request, _ := http.NewRequest("GET", "/", nil)
request.Header.Add("Accept", "test/plain")
errorHandler := HandlerFor(reg, HandlerOpts{
ErrorLog: logger,
ErrorHandling: HTTPErrorOnError,
})
continueHandler := HandlerFor(reg, HandlerOpts{
ErrorLog: logger,
ErrorHandling: ContinueOnError,
})
panicHandler := HandlerFor(reg, HandlerOpts{
ErrorLog: logger,
ErrorHandling: PanicOnError,
})
wantMsg := `error gathering metrics: error collecting metric Desc{fqName: "invalid_metric", help: "not helpful", constLabels: {}, variableLabels: []}: collect error
`
wantErrorBody := `An error has occurred during metrics gathering:
error collecting metric Desc{fqName: "invalid_metric", help: "not helpful", constLabels: {}, variableLabels: []}: collect error
`
wantOKBody := `# HELP name docstring
# TYPE name counter
name{constname="constvalue",labelname="val1"} 1
name{constname="constvalue",labelname="val2"} 1
# HELP the_count Ah-ah-ah! Thunder and lightning!
# TYPE the_count counter
the_count 0
`
errorHandler.ServeHTTP(writer, request)
if got, want := writer.Code, http.StatusInternalServerError; got != want {
t.Errorf("got HTTP status code %d, want %d", got, want)
}
if got := logBuf.String(); got != wantMsg {
t.Errorf("got log message:\n%s\nwant log message:\n%s\n", got, wantMsg)
}
if got := writer.Body.String(); got != wantErrorBody {
t.Errorf("got body:\n%s\nwant body:\n%s\n", got, wantErrorBody)
}
logBuf.Reset()
writer.Body.Reset()
writer.Code = http.StatusOK
continueHandler.ServeHTTP(writer, request)
if got, want := writer.Code, http.StatusOK; got != want {
t.Errorf("got HTTP status code %d, want %d", got, want)
}
if got := logBuf.String(); got != wantMsg {
t.Errorf("got log message %q, want %q", got, wantMsg)
}
if got := writer.Body.String(); got != wantOKBody {
t.Errorf("got body %q, want %q", got, wantOKBody)
}
defer func() {
if err := recover(); err == nil {
t.Error("expected panic from panicHandler")
}
}()
panicHandler.ServeHTTP(writer, request)
}
func TestInstrumentMetricHandler(t *testing.T) {
reg := prometheus.NewRegistry()
handler := InstrumentMetricHandler(reg, HandlerFor(reg, HandlerOpts{}))
// Do it again to test idempotency.
InstrumentMetricHandler(reg, HandlerFor(reg, HandlerOpts{}))
writer := httptest.NewRecorder()
request, _ := http.NewRequest("GET", "/", nil)
request.Header.Add("Accept", "test/plain")
handler.ServeHTTP(writer, request)
if got, want := writer.Code, http.StatusOK; got != want {
t.Errorf("got HTTP status code %d, want %d", got, want)
}
want := "promhttp_metric_handler_requests_in_flight 1\n"
if got := writer.Body.String(); !strings.Contains(got, want) {
t.Errorf("got body %q, does not contain %q", got, want)
}
want = "promhttp_metric_handler_requests_total{code=\"200\"} 0\n"
if got := writer.Body.String(); !strings.Contains(got, want) {
t.Errorf("got body %q, does not contain %q", got, want)
}
writer.Body.Reset()
handler.ServeHTTP(writer, request)
if got, want := writer.Code, http.StatusOK; got != want {
t.Errorf("got HTTP status code %d, want %d", got, want)
}
want = "promhttp_metric_handler_requests_in_flight 1\n"
if got := writer.Body.String(); !strings.Contains(got, want) {
t.Errorf("got body %q, does not contain %q", got, want)
}
want = "promhttp_metric_handler_requests_total{code=\"200\"} 1\n"
if got := writer.Body.String(); !strings.Contains(got, want) {
t.Errorf("got body %q, does not contain %q", got, want)
}
}
func TestHandlerMaxRequestsInFlight(t *testing.T) {
reg := prometheus.NewRegistry()
handler := HandlerFor(reg, HandlerOpts{MaxRequestsInFlight: 1})
w1 := httptest.NewRecorder()
w2 := httptest.NewRecorder()
w3 := httptest.NewRecorder()
request, _ := http.NewRequest("GET", "/", nil)
request.Header.Add("Accept", "test/plain")
c := blockingCollector{Block: make(chan struct{}), CollectStarted: make(chan struct{}, 1)}
reg.MustRegister(c)
rq1Done := make(chan struct{})
go func() {
handler.ServeHTTP(w1, request)
close(rq1Done)
}()
<-c.CollectStarted
handler.ServeHTTP(w2, request)
if got, want := w2.Code, http.StatusServiceUnavailable; got != want {
t.Errorf("got HTTP status code %d, want %d", got, want)
}
if got, want := w2.Body.String(), "Limit of concurrent requests reached (1), try again later.\n"; got != want {
t.Errorf("got body %q, want %q", got, want)
}
close(c.Block)
<-rq1Done
handler.ServeHTTP(w3, request)
if got, want := w3.Code, http.StatusOK; got != want {
t.Errorf("got HTTP status code %d, want %d", got, want)
}
}
func TestHandlerTimeout(t *testing.T) {
reg := prometheus.NewRegistry()
handler := HandlerFor(reg, HandlerOpts{Timeout: time.Millisecond})
w := httptest.NewRecorder()
request, _ := http.NewRequest("GET", "/", nil)
request.Header.Add("Accept", "test/plain")
c := blockingCollector{Block: make(chan struct{}), CollectStarted: make(chan struct{}, 1)}
reg.MustRegister(c)
handler.ServeHTTP(w, request)
if got, want := w.Code, http.StatusServiceUnavailable; got != want {
t.Errorf("got HTTP status code %d, want %d", got, want)
}
if got, want := w.Body.String(), "Exceeded configured timeout of 1ms.\n"; got != want {
t.Errorf("got body %q, want %q", got, want)
}
close(c.Block) // To not leak a goroutine.
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"net/http"
"time"
"github.com/prometheus/client_golang/prometheus"
)
// The RoundTripperFunc type is an adapter to allow the use of ordinary
// functions as RoundTrippers. If f is a function with the appropriate
// signature, RountTripperFunc(f) is a RoundTripper that calls f.
type RoundTripperFunc func(req *http.Request) (*http.Response, error)
// RoundTrip implements the RoundTripper interface.
func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
return rt(r)
}
// InstrumentRoundTripperInFlight is a middleware that wraps the provided
// http.RoundTripper. It sets the provided prometheus.Gauge to the number of
// requests currently handled by the wrapped http.RoundTripper.
//
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc {
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
gauge.Inc()
defer gauge.Dec()
return next.RoundTrip(r)
})
}
// InstrumentRoundTripperCounter is a middleware that wraps the provided
// http.RoundTripper to observe the request result with the provided CounterVec.
// The CounterVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. Partitioning of the CounterVec happens by HTTP status code
// and/or HTTP method if the respective instance label names are present in the
// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
//
// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
// is not incremented.
//
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper) RoundTripperFunc {
code, method := checkLabels(counter)
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
resp, err := next.RoundTrip(r)
if err == nil {
counter.With(labels(code, method, r.Method, resp.StatusCode)).Inc()
}
return resp, err
})
}
// InstrumentRoundTripperDuration is a middleware that wraps the provided
// http.RoundTripper to observe the request duration with the provided
// ObserverVec. The ObserverVec must have zero, one, or two non-const
// non-curried labels. For those, the only allowed label names are "code" and
// "method". The function panics otherwise. The Observe method of the Observer
// in the ObserverVec is called with the request duration in
// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
// respective instance label names are present in the ObserverVec. For
// unpartitioned observations, use an ObserverVec with zero labels. Note that
// partitioning of Histograms is expensive and should be used judiciously.
//
// If the wrapped RoundTripper panics or returns a non-nil error, no values are
// reported.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper) RoundTripperFunc {
code, method := checkLabels(obs)
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
start := time.Now()
resp, err := next.RoundTrip(r)
if err == nil {
obs.With(labels(code, method, r.Method, resp.StatusCode)).Observe(time.Since(start).Seconds())
}
return resp, err
})
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.8
package promhttp
import (
"context"
"crypto/tls"
"net/http"
"net/http/httptrace"
"time"
)
// InstrumentTrace is used to offer flexibility in instrumenting the available
// httptrace.ClientTrace hook functions. Each function is passed a float64
// representing the time in seconds since the start of the http request. A user
// may choose to use separately buckets Histograms, or implement custom
// instance labels on a per function basis.
type InstrumentTrace struct {
GotConn func(float64)
PutIdleConn func(float64)
GotFirstResponseByte func(float64)
Got100Continue func(float64)
DNSStart func(float64)
DNSDone func(float64)
ConnectStart func(float64)
ConnectDone func(float64)
TLSHandshakeStart func(float64)
TLSHandshakeDone func(float64)
WroteHeaders func(float64)
Wait100Continue func(float64)
WroteRequest func(float64)
}
// InstrumentRoundTripperTrace is a middleware that wraps the provided
// RoundTripper and reports times to hook functions provided in the
// InstrumentTrace struct. Hook functions that are not present in the provided
// InstrumentTrace struct are ignored. Times reported to the hook functions are
// time since the start of the request. Only with Go1.9+, those times are
// guaranteed to never be negative. (Earlier Go versions are not using a
// monotonic clock.) Note that partitioning of Histograms is expensive and
// should be used judiciously.
//
// For hook functions that receive an error as an argument, no observations are
// made in the event of a non-nil error value.
//
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc {
return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
start := time.Now()
trace := &httptrace.ClientTrace{
GotConn: func(_ httptrace.GotConnInfo) {
if it.GotConn != nil {
it.GotConn(time.Since(start).Seconds())
}
},
PutIdleConn: func(err error) {
if err != nil {
return
}
if it.PutIdleConn != nil {
it.PutIdleConn(time.Since(start).Seconds())
}
},
DNSStart: func(_ httptrace.DNSStartInfo) {
if it.DNSStart != nil {
it.DNSStart(time.Since(start).Seconds())
}
},
DNSDone: func(_ httptrace.DNSDoneInfo) {
if it.DNSDone != nil {
it.DNSDone(time.Since(start).Seconds())
}
},
ConnectStart: func(_, _ string) {
if it.ConnectStart != nil {
it.ConnectStart(time.Since(start).Seconds())
}
},
ConnectDone: func(_, _ string, err error) {
if err != nil {
return
}
if it.ConnectDone != nil {
it.ConnectDone(time.Since(start).Seconds())
}
},
GotFirstResponseByte: func() {
if it.GotFirstResponseByte != nil {
it.GotFirstResponseByte(time.Since(start).Seconds())
}
},
Got100Continue: func() {
if it.Got100Continue != nil {
it.Got100Continue(time.Since(start).Seconds())
}
},
TLSHandshakeStart: func() {
if it.TLSHandshakeStart != nil {
it.TLSHandshakeStart(time.Since(start).Seconds())
}
},
TLSHandshakeDone: func(_ tls.ConnectionState, err error) {
if err != nil {
return
}
if it.TLSHandshakeDone != nil {
it.TLSHandshakeDone(time.Since(start).Seconds())
}
},
WroteHeaders: func() {
if it.WroteHeaders != nil {
it.WroteHeaders(time.Since(start).Seconds())
}
},
Wait100Continue: func() {
if it.Wait100Continue != nil {
it.Wait100Continue(time.Since(start).Seconds())
}
},
WroteRequest: func(_ httptrace.WroteRequestInfo) {
if it.WroteRequest != nil {
it.WroteRequest(time.Since(start).Seconds())
}
},
}
r = r.WithContext(httptrace.WithClientTrace(context.Background(), trace))
return next.RoundTrip(r)
})
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.8
package promhttp
import (
"log"
"net/http"
"testing"
"time"
"github.com/prometheus/client_golang/prometheus"
)
func TestClientMiddlewareAPI(t *testing.T) {
client := http.DefaultClient
client.Timeout = 1 * time.Second
reg := prometheus.NewRegistry()
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "client_in_flight_requests",
Help: "A gauge of in-flight requests for the wrapped client.",
})
counter := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "client_api_requests_total",
Help: "A counter for requests from the wrapped client.",
},
[]string{"code", "method"},
)
dnsLatencyVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "dns_duration_seconds",
Help: "Trace dns latency histogram.",
Buckets: []float64{.005, .01, .025, .05},
},
[]string{"event"},
)
tlsLatencyVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "tls_duration_seconds",
Help: "Trace tls latency histogram.",
Buckets: []float64{.05, .1, .25, .5},
},
[]string{"event"},
)
histVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "request_duration_seconds",
Help: "A histogram of request latencies.",
Buckets: prometheus.DefBuckets,
},
[]string{"method"},
)
reg.MustRegister(counter, tlsLatencyVec, dnsLatencyVec, histVec, inFlightGauge)
trace := &InstrumentTrace{
DNSStart: func(t float64) {
dnsLatencyVec.WithLabelValues("dns_start")
},
DNSDone: func(t float64) {
dnsLatencyVec.WithLabelValues("dns_done")
},
TLSHandshakeStart: func(t float64) {
tlsLatencyVec.WithLabelValues("tls_handshake_start")
},
TLSHandshakeDone: func(t float64) {
tlsLatencyVec.WithLabelValues("tls_handshake_done")
},
}
client.Transport = InstrumentRoundTripperInFlight(inFlightGauge,
InstrumentRoundTripperCounter(counter,
InstrumentRoundTripperTrace(trace,
InstrumentRoundTripperDuration(histVec, http.DefaultTransport),
),
),
)
resp, err := client.Get("http://google.com")
if err != nil {
t.Fatalf("%v", err)
}
defer resp.Body.Close()
}
func ExampleInstrumentRoundTripperDuration() {
client := http.DefaultClient
client.Timeout = 1 * time.Second
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "client_in_flight_requests",
Help: "A gauge of in-flight requests for the wrapped client.",
})
counter := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "client_api_requests_total",
Help: "A counter for requests from the wrapped client.",
},
[]string{"code", "method"},
)
// dnsLatencyVec uses custom buckets based on expected dns durations.
// It has an instance label "event", which is set in the
// DNSStart and DNSDonehook functions defined in the
// InstrumentTrace struct below.
dnsLatencyVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "dns_duration_seconds",
Help: "Trace dns latency histogram.",
Buckets: []float64{.005, .01, .025, .05},
},
[]string{"event"},
)
// tlsLatencyVec uses custom buckets based on expected tls durations.
// It has an instance label "event", which is set in the
// TLSHandshakeStart and TLSHandshakeDone hook functions defined in the
// InstrumentTrace struct below.
tlsLatencyVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "tls_duration_seconds",
Help: "Trace tls latency histogram.",
Buckets: []float64{.05, .1, .25, .5},
},
[]string{"event"},
)
// histVec has no labels, making it a zero-dimensional ObserverVec.
histVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "request_duration_seconds",
Help: "A histogram of request latencies.",
Buckets: prometheus.DefBuckets,
},
[]string{},
)
// Register all of the metrics in the standard registry.
prometheus.MustRegister(counter, tlsLatencyVec, dnsLatencyVec, histVec, inFlightGauge)
// Define functions for the available httptrace.ClientTrace hook
// functions that we want to instrument.
trace := &InstrumentTrace{
DNSStart: func(t float64) {
dnsLatencyVec.WithLabelValues("dns_start")
},
DNSDone: func(t float64) {
dnsLatencyVec.WithLabelValues("dns_done")
},
TLSHandshakeStart: func(t float64) {
tlsLatencyVec.WithLabelValues("tls_handshake_start")
},
TLSHandshakeDone: func(t float64) {
tlsLatencyVec.WithLabelValues("tls_handshake_done")
},
}
// Wrap the default RoundTripper with middleware.
roundTripper := InstrumentRoundTripperInFlight(inFlightGauge,
InstrumentRoundTripperCounter(counter,
InstrumentRoundTripperTrace(trace,
InstrumentRoundTripperDuration(histVec, http.DefaultTransport),
),
),
)
// Set the RoundTripper on our client.
client.Transport = roundTripper
resp, err := client.Get("http://google.com")
if err != nil {
log.Printf("error: %v", err)
}
defer resp.Body.Close()
}

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@ -0,0 +1,447 @@
// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"errors"
"net/http"
"strconv"
"strings"
"time"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/client_golang/prometheus"
)
// magicString is used for the hacky label test in checkLabels. Remove once fixed.
const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa"
// InstrumentHandlerInFlight is a middleware that wraps the provided
// http.Handler. It sets the provided prometheus.Gauge to the number of
// requests currently handled by the wrapped http.Handler.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
g.Inc()
defer g.Dec()
next.ServeHTTP(w, r)
})
}
// InstrumentHandlerDuration is a middleware that wraps the provided
// http.Handler to observe the request duration with the provided ObserverVec.
// The ObserverVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. The Observe method of the Observer in the ObserverVec is
// called with the request duration in seconds. Partitioning happens by HTTP
// status code and/or HTTP method if the respective instance label names are
// present in the ObserverVec. For unpartitioned observations, use an
// ObserverVec with zero labels. Note that partitioning of Histograms is
// expensive and should be used judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, no values are reported.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
code, method := checkLabels(obs)
if code {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
obs.With(labels(code, method, r.Method, d.Status())).Observe(time.Since(now).Seconds())
})
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
next.ServeHTTP(w, r)
obs.With(labels(code, method, r.Method, 0)).Observe(time.Since(now).Seconds())
})
}
// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
// to observe the request result with the provided CounterVec. The CounterVec
// must have zero, one, or two non-const non-curried labels. For those, the only
// allowed label names are "code" and "method". The function panics
// otherwise. Partitioning of the CounterVec happens by HTTP status code and/or
// HTTP method if the respective instance label names are present in the
// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, the Counter is not incremented.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) http.HandlerFunc {
code, method := checkLabels(counter)
if code {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
counter.With(labels(code, method, r.Method, d.Status())).Inc()
})
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
next.ServeHTTP(w, r)
counter.With(labels(code, method, r.Method, 0)).Inc()
})
}
// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
// http.Handler to observe with the provided ObserverVec the request duration
// until the response headers are written. The ObserverVec must have zero, one,
// or two non-const non-curried labels. For those, the only allowed label names
// are "code" and "method". The function panics otherwise. The Observe method of
// the Observer in the ObserverVec is called with the request duration in
// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
// respective instance label names are present in the ObserverVec. For
// unpartitioned observations, use an ObserverVec with zero labels. Note that
// partitioning of Histograms is expensive and should be used judiciously.
//
// If the wrapped Handler panics before calling WriteHeader, no value is
// reported.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
code, method := checkLabels(obs)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
d := newDelegator(w, func(status int) {
obs.With(labels(code, method, r.Method, status)).Observe(time.Since(now).Seconds())
})
next.ServeHTTP(d, r)
})
}
// InstrumentHandlerRequestSize is a middleware that wraps the provided
// http.Handler to observe the request size with the provided ObserverVec. The
// ObserverVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. The Observe method of the Observer in the ObserverVec is
// called with the request size in bytes. Partitioning happens by HTTP status
// code and/or HTTP method if the respective instance label names are present in
// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
// labels. Note that partitioning of Histograms is expensive and should be used
// judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, no values are reported.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
code, method := checkLabels(obs)
if code {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
size := computeApproximateRequestSize(r)
obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(size))
})
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
next.ServeHTTP(w, r)
size := computeApproximateRequestSize(r)
obs.With(labels(code, method, r.Method, 0)).Observe(float64(size))
})
}
// InstrumentHandlerResponseSize is a middleware that wraps the provided
// http.Handler to observe the response size with the provided ObserverVec. The
// ObserverVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. The Observe method of the Observer in the ObserverVec is
// called with the response size in bytes. Partitioning happens by HTTP status
// code and/or HTTP method if the respective instance label names are present in
// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
// labels. Note that partitioning of Histograms is expensive and should be used
// judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, no values are reported.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler) http.Handler {
code, method := checkLabels(obs)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(d.Written()))
})
}
func checkLabels(c prometheus.Collector) (code bool, method bool) {
// TODO(beorn7): Remove this hacky way to check for instance labels
// once Descriptors can have their dimensionality queried.
var (
desc *prometheus.Desc
m prometheus.Metric
pm dto.Metric
lvs []string
)
// Get the Desc from the Collector.
descc := make(chan *prometheus.Desc, 1)
c.Describe(descc)
select {
case desc = <-descc:
default:
panic("no description provided by collector")
}
select {
case <-descc:
panic("more than one description provided by collector")
default:
}
close(descc)
// Create a ConstMetric with the Desc. Since we don't know how many
// variable labels there are, try for as long as it needs.
for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
}
// Write out the metric into a proto message and look at the labels.
// If the value is not the magicString, it is a constLabel, which doesn't interest us.
// If the label is curried, it doesn't interest us.
// In all other cases, only "code" or "method" is allowed.
if err := m.Write(&pm); err != nil {
panic("error checking metric for labels")
}
for _, label := range pm.Label {
name, value := label.GetName(), label.GetValue()
if value != magicString || isLabelCurried(c, name) {
continue
}
switch name {
case "code":
code = true
case "method":
method = true
default:
panic("metric partitioned with non-supported labels")
}
}
return
}
func isLabelCurried(c prometheus.Collector, label string) bool {
// This is even hackier than the label test above.
// We essentially try to curry again and see if it works.
// But for that, we need to type-convert to the two
// types we use here, ObserverVec or *CounterVec.
switch v := c.(type) {
case *prometheus.CounterVec:
if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
return false
}
case prometheus.ObserverVec:
if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
return false
}
default:
panic("unsupported metric vec type")
}
return true
}
// emptyLabels is a one-time allocation for non-partitioned metrics to avoid
// unnecessary allocations on each request.
var emptyLabels = prometheus.Labels{}
func labels(code, method bool, reqMethod string, status int) prometheus.Labels {
if !(code || method) {
return emptyLabels
}
labels := prometheus.Labels{}
if code {
labels["code"] = sanitizeCode(status)
}
if method {
labels["method"] = sanitizeMethod(reqMethod)
}
return labels
}
func computeApproximateRequestSize(r *http.Request) int {
s := 0
if r.URL != nil {
s += len(r.URL.String())
}
s += len(r.Method)
s += len(r.Proto)
for name, values := range r.Header {
s += len(name)
for _, value := range values {
s += len(value)
}
}
s += len(r.Host)
// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
if r.ContentLength != -1 {
s += int(r.ContentLength)
}
return s
}
func sanitizeMethod(m string) string {
switch m {
case "GET", "get":
return "get"
case "PUT", "put":
return "put"
case "HEAD", "head":
return "head"
case "POST", "post":
return "post"
case "DELETE", "delete":
return "delete"
case "CONNECT", "connect":
return "connect"
case "OPTIONS", "options":
return "options"
case "NOTIFY", "notify":
return "notify"
default:
return strings.ToLower(m)
}
}
// If the wrapped http.Handler has not set a status code, i.e. the value is
// currently 0, santizeCode will return 200, for consistency with behavior in
// the stdlib.
func sanitizeCode(s int) string {
switch s {
case 100:
return "100"
case 101:
return "101"
case 200, 0:
return "200"
case 201:
return "201"
case 202:
return "202"
case 203:
return "203"
case 204:
return "204"
case 205:
return "205"
case 206:
return "206"
case 300:
return "300"
case 301:
return "301"
case 302:
return "302"
case 304:
return "304"
case 305:
return "305"
case 307:
return "307"
case 400:
return "400"
case 401:
return "401"
case 402:
return "402"
case 403:
return "403"
case 404:
return "404"
case 405:
return "405"
case 406:
return "406"
case 407:
return "407"
case 408:
return "408"
case 409:
return "409"
case 410:
return "410"
case 411:
return "411"
case 412:
return "412"
case 413:
return "413"
case 414:
return "414"
case 415:
return "415"
case 416:
return "416"
case 417:
return "417"
case 418:
return "418"
case 500:
return "500"
case 501:
return "501"
case 502:
return "502"
case 503:
return "503"
case 504:
return "504"
case 505:
return "505"
case 428:
return "428"
case 429:
return "429"
case 431:
return "431"
case 511:
return "511"
default:
return strconv.Itoa(s)
}
}

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@ -0,0 +1,401 @@
// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"io"
"log"
"net/http"
"net/http/httptest"
"testing"
"github.com/prometheus/client_golang/prometheus"
)
func TestLabelCheck(t *testing.T) {
scenarios := map[string]struct {
varLabels []string
constLabels []string
curriedLabels []string
ok bool
}{
"empty": {
varLabels: []string{},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"code as single var label": {
varLabels: []string{"code"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"method as single var label": {
varLabels: []string{"method"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"cade and method as var labels": {
varLabels: []string{"method", "code"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"valid case with all labels used": {
varLabels: []string{"code", "method"},
constLabels: []string{"foo", "bar"},
curriedLabels: []string{"dings", "bums"},
ok: true,
},
"unsupported var label": {
varLabels: []string{"foo"},
constLabels: []string{},
curriedLabels: []string{},
ok: false,
},
"mixed var labels": {
varLabels: []string{"method", "foo", "code"},
constLabels: []string{},
curriedLabels: []string{},
ok: false,
},
"unsupported var label but curried": {
varLabels: []string{},
constLabels: []string{},
curriedLabels: []string{"foo"},
ok: true,
},
"mixed var labels but unsupported curried": {
varLabels: []string{"code", "method"},
constLabels: []string{},
curriedLabels: []string{"foo"},
ok: true,
},
"supported label as const and curry": {
varLabels: []string{},
constLabels: []string{"code"},
curriedLabels: []string{"method"},
ok: true,
},
"supported label as const and curry with unsupported as var": {
varLabels: []string{"foo"},
constLabels: []string{"code"},
curriedLabels: []string{"method"},
ok: false,
},
}
for name, sc := range scenarios {
t.Run(name, func(t *testing.T) {
constLabels := prometheus.Labels{}
for _, l := range sc.constLabels {
constLabels[l] = "dummy"
}
c := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "c",
Help: "c help",
ConstLabels: constLabels,
},
append(sc.varLabels, sc.curriedLabels...),
)
o := prometheus.ObserverVec(prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "c",
Help: "c help",
ConstLabels: constLabels,
},
append(sc.varLabels, sc.curriedLabels...),
))
for _, l := range sc.curriedLabels {
c = c.MustCurryWith(prometheus.Labels{l: "dummy"})
o = o.MustCurryWith(prometheus.Labels{l: "dummy"})
}
func() {
defer func() {
if err := recover(); err != nil {
if sc.ok {
t.Error("unexpected panic:", err)
}
} else if !sc.ok {
t.Error("expected panic")
}
}()
InstrumentHandlerCounter(c, nil)
}()
func() {
defer func() {
if err := recover(); err != nil {
if sc.ok {
t.Error("unexpected panic:", err)
}
} else if !sc.ok {
t.Error("expected panic")
}
}()
InstrumentHandlerDuration(o, nil)
}()
if sc.ok {
// Test if wantCode and wantMethod were detected correctly.
var wantCode, wantMethod bool
for _, l := range sc.varLabels {
if l == "code" {
wantCode = true
}
if l == "method" {
wantMethod = true
}
}
gotCode, gotMethod := checkLabels(c)
if gotCode != wantCode {
t.Errorf("wanted code=%t for counter, got code=%t", wantCode, gotCode)
}
if gotMethod != wantMethod {
t.Errorf("wanted method=%t for counter, got method=%t", wantMethod, gotMethod)
}
gotCode, gotMethod = checkLabels(o)
if gotCode != wantCode {
t.Errorf("wanted code=%t for observer, got code=%t", wantCode, gotCode)
}
if gotMethod != wantMethod {
t.Errorf("wanted method=%t for observer, got method=%t", wantMethod, gotMethod)
}
}
})
}
}
func TestMiddlewareAPI(t *testing.T) {
reg := prometheus.NewRegistry()
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "in_flight_requests",
Help: "A gauge of requests currently being served by the wrapped handler.",
})
counter := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "api_requests_total",
Help: "A counter for requests to the wrapped handler.",
},
[]string{"code", "method"},
)
histVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "response_duration_seconds",
Help: "A histogram of request latencies.",
Buckets: prometheus.DefBuckets,
ConstLabels: prometheus.Labels{"handler": "api"},
},
[]string{"method"},
)
writeHeaderVec := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "write_header_duration_seconds",
Help: "A histogram of time to first write latencies.",
Buckets: prometheus.DefBuckets,
ConstLabels: prometheus.Labels{"handler": "api"},
},
[]string{},
)
responseSize := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "push_request_size_bytes",
Help: "A histogram of request sizes for requests.",
Buckets: []float64{200, 500, 900, 1500},
},
[]string{},
)
handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("OK"))
})
reg.MustRegister(inFlightGauge, counter, histVec, responseSize, writeHeaderVec)
chain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerCounter(counter,
InstrumentHandlerDuration(histVec,
InstrumentHandlerTimeToWriteHeader(writeHeaderVec,
InstrumentHandlerResponseSize(responseSize, handler),
),
),
),
)
r, _ := http.NewRequest("GET", "www.example.com", nil)
w := httptest.NewRecorder()
chain.ServeHTTP(w, r)
}
func TestInstrumentTimeToFirstWrite(t *testing.T) {
var i int
dobs := &responseWriterDelegator{
ResponseWriter: httptest.NewRecorder(),
observeWriteHeader: func(status int) {
i = status
},
}
d := newDelegator(dobs, nil)
d.WriteHeader(http.StatusOK)
if i != http.StatusOK {
t.Fatalf("failed to execute observeWriteHeader")
}
}
// testResponseWriter is an http.ResponseWriter that also implements
// http.CloseNotifier, http.Flusher, and io.ReaderFrom.
type testResponseWriter struct {
closeNotifyCalled, flushCalled, readFromCalled bool
}
func (t *testResponseWriter) Header() http.Header { return nil }
func (t *testResponseWriter) Write([]byte) (int, error) { return 0, nil }
func (t *testResponseWriter) WriteHeader(int) {}
func (t *testResponseWriter) CloseNotify() <-chan bool {
t.closeNotifyCalled = true
return nil
}
func (t *testResponseWriter) Flush() { t.flushCalled = true }
func (t *testResponseWriter) ReadFrom(io.Reader) (int64, error) {
t.readFromCalled = true
return 0, nil
}
// testFlusher is an http.ResponseWriter that also implements http.Flusher.
type testFlusher struct {
flushCalled bool
}
func (t *testFlusher) Header() http.Header { return nil }
func (t *testFlusher) Write([]byte) (int, error) { return 0, nil }
func (t *testFlusher) WriteHeader(int) {}
func (t *testFlusher) Flush() { t.flushCalled = true }
func TestInterfaceUpgrade(t *testing.T) {
w := &testResponseWriter{}
d := newDelegator(w, nil)
d.(http.CloseNotifier).CloseNotify()
if !w.closeNotifyCalled {
t.Error("CloseNotify not called")
}
d.(http.Flusher).Flush()
if !w.flushCalled {
t.Error("Flush not called")
}
d.(io.ReaderFrom).ReadFrom(nil)
if !w.readFromCalled {
t.Error("ReadFrom not called")
}
if _, ok := d.(http.Hijacker); ok {
t.Error("delegator unexpectedly implements http.Hijacker")
}
f := &testFlusher{}
d = newDelegator(f, nil)
if _, ok := d.(http.CloseNotifier); ok {
t.Error("delegator unexpectedly implements http.CloseNotifier")
}
d.(http.Flusher).Flush()
if !w.flushCalled {
t.Error("Flush not called")
}
if _, ok := d.(io.ReaderFrom); ok {
t.Error("delegator unexpectedly implements io.ReaderFrom")
}
if _, ok := d.(http.Hijacker); ok {
t.Error("delegator unexpectedly implements http.Hijacker")
}
}
func ExampleInstrumentHandlerDuration() {
inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "in_flight_requests",
Help: "A gauge of requests currently being served by the wrapped handler.",
})
counter := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "api_requests_total",
Help: "A counter for requests to the wrapped handler.",
},
[]string{"code", "method"},
)
// duration is partitioned by the HTTP method and handler. It uses custom
// buckets based on the expected request duration.
duration := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "request_duration_seconds",
Help: "A histogram of latencies for requests.",
Buckets: []float64{.25, .5, 1, 2.5, 5, 10},
},
[]string{"handler", "method"},
)
// responseSize has no labels, making it a zero-dimensional
// ObserverVec.
responseSize := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "response_size_bytes",
Help: "A histogram of response sizes for requests.",
Buckets: []float64{200, 500, 900, 1500},
},
[]string{},
)
// Create the handlers that will be wrapped by the middleware.
pushHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Push"))
})
pullHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Pull"))
})
// Register all of the metrics in the standard registry.
prometheus.MustRegister(inFlightGauge, counter, duration, responseSize)
// Instrument the handlers with all the metrics, injecting the "handler"
// label by currying.
pushChain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "push"}),
InstrumentHandlerCounter(counter,
InstrumentHandlerResponseSize(responseSize, pushHandler),
),
),
)
pullChain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "pull"}),
InstrumentHandlerCounter(counter,
InstrumentHandlerResponseSize(responseSize, pullHandler),
),
),
)
http.Handle("/metrics", Handler())
http.Handle("/push", pushChain)
http.Handle("/pull", pullChain)
if err := http.ListenAndServe(":3000", nil); err != nil {
log.Fatal(err)
}
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package push
// This file contains only deprecated code. Remove after v0.9 is released.
import (
"bytes"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"os"
"strings"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/common/model"
"github.com/prometheus/client_golang/prometheus"
)
// FromGatherer triggers a metric collection by the provided Gatherer (which is
// usually implemented by a prometheus.Registry) and pushes all gathered metrics
// to the Pushgateway specified by url, using the provided job name and the
// (optional) further grouping labels (the grouping map may be nil). See the
// Pushgateway documentation for detailed implications of the job and other
// grouping labels. Neither the job name nor any grouping label value may
// contain a "/". The metrics pushed must not contain a job label of their own
// nor any of the grouping labels.
//
// You can use just host:port or ip:port as url, in which case 'http://' is
// added automatically. You can also include the schema in the URL. However, do
// not include the '/metrics/jobs/...' part.
//
// Note that all previously pushed metrics with the same job and other grouping
// labels will be replaced with the metrics pushed by this call. (It uses HTTP
// method 'PUT' to push to the Pushgateway.)
//
// Deprecated: Please use a Pusher created with New instead.
func FromGatherer(job string, grouping map[string]string, url string, g prometheus.Gatherer) error {
return push(job, grouping, url, g, "PUT")
}
// AddFromGatherer works like FromGatherer, but only previously pushed metrics
// with the same name (and the same job and other grouping labels) will be
// replaced. (It uses HTTP method 'POST' to push to the Pushgateway.)
//
// Deprecated: Please use a Pusher created with New instead.
func AddFromGatherer(job string, grouping map[string]string, url string, g prometheus.Gatherer) error {
return push(job, grouping, url, g, "POST")
}
func push(job string, grouping map[string]string, pushURL string, g prometheus.Gatherer, method string) error {
if !strings.Contains(pushURL, "://") {
pushURL = "http://" + pushURL
}
if strings.HasSuffix(pushURL, "/") {
pushURL = pushURL[:len(pushURL)-1]
}
if strings.Contains(job, "/") {
return fmt.Errorf("job contains '/': %s", job)
}
urlComponents := []string{url.QueryEscape(job)}
for ln, lv := range grouping {
if !model.LabelName(ln).IsValid() {
return fmt.Errorf("grouping label has invalid name: %s", ln)
}
if strings.Contains(lv, "/") {
return fmt.Errorf("value of grouping label %s contains '/': %s", ln, lv)
}
urlComponents = append(urlComponents, ln, lv)
}
pushURL = fmt.Sprintf("%s/metrics/job/%s", pushURL, strings.Join(urlComponents, "/"))
mfs, err := g.Gather()
if err != nil {
return err
}
buf := &bytes.Buffer{}
enc := expfmt.NewEncoder(buf, expfmt.FmtProtoDelim)
// Check for pre-existing grouping labels:
for _, mf := range mfs {
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
if l.GetName() == "job" {
return fmt.Errorf("pushed metric %s (%s) already contains a job label", mf.GetName(), m)
}
if _, ok := grouping[l.GetName()]; ok {
return fmt.Errorf(
"pushed metric %s (%s) already contains grouping label %s",
mf.GetName(), m, l.GetName(),
)
}
}
}
enc.Encode(mf)
}
req, err := http.NewRequest(method, pushURL, buf)
if err != nil {
return err
}
req.Header.Set(contentTypeHeader, string(expfmt.FmtProtoDelim))
resp, err := http.DefaultClient.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != 202 {
body, _ := ioutil.ReadAll(resp.Body) // Ignore any further error as this is for an error message only.
return fmt.Errorf("unexpected status code %d while pushing to %s: %s", resp.StatusCode, pushURL, body)
}
return nil
}
// Collectors works like FromGatherer, but it does not use a Gatherer. Instead,
// it collects from the provided collectors directly. It is a convenient way to
// push only a few metrics.
//
// Deprecated: Please use a Pusher created with New instead.
func Collectors(job string, grouping map[string]string, url string, collectors ...prometheus.Collector) error {
return pushCollectors(job, grouping, url, "PUT", collectors...)
}
// AddCollectors works like AddFromGatherer, but it does not use a Gatherer.
// Instead, it collects from the provided collectors directly. It is a
// convenient way to push only a few metrics.
//
// Deprecated: Please use a Pusher created with New instead.
func AddCollectors(job string, grouping map[string]string, url string, collectors ...prometheus.Collector) error {
return pushCollectors(job, grouping, url, "POST", collectors...)
}
func pushCollectors(job string, grouping map[string]string, url, method string, collectors ...prometheus.Collector) error {
r := prometheus.NewRegistry()
for _, collector := range collectors {
if err := r.Register(collector); err != nil {
return err
}
}
return push(job, grouping, url, r, method)
}
// HostnameGroupingKey returns a label map with the only entry
// {instance="<hostname>"}. This can be conveniently used as the grouping
// parameter if metrics should be pushed with the hostname as label. The
// returned map is created upon each call so that the caller is free to add more
// labels to the map.
//
// Deprecated: Usually, metrics pushed to the Pushgateway should not be
// host-centric. (You would use https://github.com/prometheus/node_exporter in
// that case.) If you have the need to add the hostname to the grouping key, you
// are probably doing something wrong. See
// https://prometheus.io/docs/practices/pushing/ for details.
func HostnameGroupingKey() map[string]string {
hostname, err := os.Hostname()
if err != nil {
return map[string]string{"instance": "unknown"}
}
return map[string]string{"instance": hostname}
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package push_test
import (
"fmt"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/push"
)
var (
completionTime = prometheus.NewGauge(prometheus.GaugeOpts{
Name: "db_backup_last_completion_timestamp_seconds",
Help: "The timestamp of the last completion of a DB backup, successful or not.",
})
successTime = prometheus.NewGauge(prometheus.GaugeOpts{
Name: "db_backup_last_success_timestamp_seconds",
Help: "The timestamp of the last successful completion of a DB backup.",
})
duration = prometheus.NewGauge(prometheus.GaugeOpts{
Name: "db_backup_duration_seconds",
Help: "The duration of the last DB backup in seconds.",
})
records = prometheus.NewGauge(prometheus.GaugeOpts{
Name: "db_backup_records_processed",
Help: "The number of records processed in the last DB backup.",
})
)
func performBackup() (int, error) {
// Perform the backup and return the number of backed up records and any
// applicable error.
// ...
return 42, nil
}
func ExamplePusher_Add() {
// We use a registry here to benefit from the consistency checks that
// happen during registration.
registry := prometheus.NewRegistry()
registry.MustRegister(completionTime, duration, records)
// Note that successTime is not registered.
pusher := push.New("http://pushgateway:9091", "db_backup").Gatherer(registry)
start := time.Now()
n, err := performBackup()
records.Set(float64(n))
// Note that time.Since only uses a monotonic clock in Go1.9+.
duration.Set(time.Since(start).Seconds())
completionTime.SetToCurrentTime()
if err != nil {
fmt.Println("DB backup failed:", err)
} else {
// Add successTime to pusher only in case of success.
// We could as well register it with the registry.
// This example, however, demonstrates that you can
// mix Gatherers and Collectors when handling a Pusher.
pusher.Collector(successTime)
successTime.SetToCurrentTime()
}
// Add is used here rather than Push to not delete a previously pushed
// success timestamp in case of a failure of this backup.
if err := pusher.Add(); err != nil {
fmt.Println("Could not push to Pushgateway:", err)
}
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package push_test
import (
"fmt"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/push"
)
func ExamplePusher_Push() {
completionTime := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "db_backup_last_completion_timestamp_seconds",
Help: "The timestamp of the last successful completion of a DB backup.",
})
completionTime.SetToCurrentTime()
if err := push.New("http://pushgateway:9091", "db_backup").
Collector(completionTime).
Grouping("db", "customers").
Push(); err != nil {
fmt.Println("Could not push completion time to Pushgateway:", err)
}
}

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package push provides functions to push metrics to a Pushgateway. It uses a
// builder approach. Create a Pusher with New and then add the various options
// by using its methods, finally calling Add or Push, like this:
//
// // Easy case:
// push.New("http://example.org/metrics", "my_job").Gatherer(myRegistry).Push()
//
// // Complex case:
// push.New("http://example.org/metrics", "my_job").
// Collector(myCollector1).
// Collector(myCollector2).
// Grouping("zone", "xy").
// Client(&myHTTPClient).
// BasicAuth("top", "secret").
// Add()
//
// See the examples section for more detailed examples.
//
// See the documentation of the Pushgateway to understand the meaning of
// the grouping key and the differences between Push and Add:
// https://github.com/prometheus/pushgateway
package push
import (
"bytes"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"strings"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/common/model"
"github.com/prometheus/client_golang/prometheus"
)
const contentTypeHeader = "Content-Type"
// Pusher manages a push to the Pushgateway. Use New to create one, configure it
// with its methods, and finally use the Add or Push method to push.
type Pusher struct {
error error
url, job string
grouping map[string]string
gatherers prometheus.Gatherers
registerer prometheus.Registerer
client *http.Client
useBasicAuth bool
username, password string
}
// New creates a new Pusher to push to the provided URL with the provided job
// name. You can use just host:port or ip:port as url, in which case “http://”
// is added automatically. Alternatively, include the schema in the
// URL. However, do not include the “/metrics/jobs/…” part.
//
// Note that until https://github.com/prometheus/pushgateway/issues/97 is
// resolved, a “/” character in the job name is prohibited.
func New(url, job string) *Pusher {
var (
reg = prometheus.NewRegistry()
err error
)
if !strings.Contains(url, "://") {
url = "http://" + url
}
if strings.HasSuffix(url, "/") {
url = url[:len(url)-1]
}
if strings.Contains(job, "/") {
err = fmt.Errorf("job contains '/': %s", job)
}
return &Pusher{
error: err,
url: url,
job: job,
grouping: map[string]string{},
gatherers: prometheus.Gatherers{reg},
registerer: reg,
client: &http.Client{},
}
}
// Push collects/gathers all metrics from all Collectors and Gatherers added to
// this Pusher. Then, it pushes them to the Pushgateway configured while
// creating this Pusher, using the configured job name and any added grouping
// labels as grouping key. All previously pushed metrics with the same job and
// other grouping labels will be replaced with the metrics pushed by this
// call. (It uses HTTP method “PUT” to push to the Pushgateway.)
//
// Push returns the first error encountered by any method call (including this
// one) in the lifetime of the Pusher.
func (p *Pusher) Push() error {
return p.push("PUT")
}
// Add works like push, but only previously pushed metrics with the same name
// (and the same job and other grouping labels) will be replaced. (It uses HTTP
// method “POST” to push to the Pushgateway.)
func (p *Pusher) Add() error {
return p.push("POST")
}
// Gatherer adds a Gatherer to the Pusher, from which metrics will be gathered
// to push them to the Pushgateway. The gathered metrics must not contain a job
// label of their own.
//
// For convenience, this method returns a pointer to the Pusher itself.
func (p *Pusher) Gatherer(g prometheus.Gatherer) *Pusher {
p.gatherers = append(p.gatherers, g)
return p
}
// Collector adds a Collector to the Pusher, from which metrics will be
// collected to push them to the Pushgateway. The collected metrics must not
// contain a job label of their own.
//
// For convenience, this method returns a pointer to the Pusher itself.
func (p *Pusher) Collector(c prometheus.Collector) *Pusher {
if p.error == nil {
p.error = p.registerer.Register(c)
}
return p
}
// Grouping adds a label pair to the grouping key of the Pusher, replacing any
// previously added label pair with the same label name. Note that setting any
// labels in the grouping key that are already contained in the metrics to push
// will lead to an error.
//
// For convenience, this method returns a pointer to the Pusher itself.
//
// Note that until https://github.com/prometheus/pushgateway/issues/97 is
// resolved, this method does not allow a “/” character in the label value.
func (p *Pusher) Grouping(name, value string) *Pusher {
if p.error == nil {
if !model.LabelName(name).IsValid() {
p.error = fmt.Errorf("grouping label has invalid name: %s", name)
return p
}
if strings.Contains(value, "/") {
p.error = fmt.Errorf("value of grouping label %s contains '/': %s", name, value)
return p
}
p.grouping[name] = value
}
return p
}
// Client sets a custom HTTP client for the Pusher. For convenience, this method
// returns a pointer to the Pusher itself.
func (p *Pusher) Client(c *http.Client) *Pusher {
p.client = c
return p
}
// BasicAuth configures the Pusher to use HTTP Basic Authentication with the
// provided username and password. For convenience, this method returns a
// pointer to the Pusher itself.
func (p *Pusher) BasicAuth(username, password string) *Pusher {
p.useBasicAuth = true
p.username = username
p.password = password
return p
}
func (p *Pusher) push(method string) error {
if p.error != nil {
return p.error
}
urlComponents := []string{url.QueryEscape(p.job)}
for ln, lv := range p.grouping {
urlComponents = append(urlComponents, ln, lv)
}
pushURL := fmt.Sprintf("%s/metrics/job/%s", p.url, strings.Join(urlComponents, "/"))
mfs, err := p.gatherers.Gather()
if err != nil {
return err
}
buf := &bytes.Buffer{}
enc := expfmt.NewEncoder(buf, expfmt.FmtProtoDelim)
// Check for pre-existing grouping labels:
for _, mf := range mfs {
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
if l.GetName() == "job" {
return fmt.Errorf("pushed metric %s (%s) already contains a job label", mf.GetName(), m)
}
if _, ok := p.grouping[l.GetName()]; ok {
return fmt.Errorf(
"pushed metric %s (%s) already contains grouping label %s",
mf.GetName(), m, l.GetName(),
)
}
}
}
enc.Encode(mf)
}
req, err := http.NewRequest(method, pushURL, buf)
if err != nil {
return err
}
if p.useBasicAuth {
req.SetBasicAuth(p.username, p.password)
}
req.Header.Set(contentTypeHeader, string(expfmt.FmtProtoDelim))
resp, err := p.client.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != 202 {
body, _ := ioutil.ReadAll(resp.Body) // Ignore any further error as this is for an error message only.
return fmt.Errorf("unexpected status code %d while pushing to %s: %s", resp.StatusCode, pushURL, body)
}
return nil
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package push
import (
"bytes"
"io/ioutil"
"net/http"
"net/http/httptest"
"testing"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/client_golang/prometheus"
)
func TestPush(t *testing.T) {
var (
lastMethod string
lastBody []byte
lastPath string
)
// Fake a Pushgateway that always responds with 202.
pgwOK := httptest.NewServer(
http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
lastMethod = r.Method
var err error
lastBody, err = ioutil.ReadAll(r.Body)
if err != nil {
t.Fatal(err)
}
lastPath = r.URL.EscapedPath()
w.Header().Set("Content-Type", `text/plain; charset=utf-8`)
w.WriteHeader(http.StatusAccepted)
}),
)
defer pgwOK.Close()
// Fake a Pushgateway that always responds with 500.
pgwErr := httptest.NewServer(
http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
http.Error(w, "fake error", http.StatusInternalServerError)
}),
)
defer pgwErr.Close()
metric1 := prometheus.NewCounter(prometheus.CounterOpts{
Name: "testname1",
Help: "testhelp1",
})
metric2 := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "testname2",
Help: "testhelp2",
ConstLabels: prometheus.Labels{"foo": "bar", "dings": "bums"},
})
reg := prometheus.NewRegistry()
reg.MustRegister(metric1)
reg.MustRegister(metric2)
mfs, err := reg.Gather()
if err != nil {
t.Fatal(err)
}
buf := &bytes.Buffer{}
enc := expfmt.NewEncoder(buf, expfmt.FmtProtoDelim)
for _, mf := range mfs {
if err := enc.Encode(mf); err != nil {
t.Fatal(err)
}
}
wantBody := buf.Bytes()
// Push some Collectors, all good.
if err := New(pgwOK.URL, "testjob").
Collector(metric1).
Collector(metric2).
Push(); err != nil {
t.Fatal(err)
}
if lastMethod != "PUT" {
t.Error("want method PUT for Push, got", lastMethod)
}
if bytes.Compare(lastBody, wantBody) != 0 {
t.Errorf("got body %v, want %v", lastBody, wantBody)
}
if lastPath != "/metrics/job/testjob" {
t.Error("unexpected path:", lastPath)
}
// Add some Collectors, with nil grouping, all good.
if err := New(pgwOK.URL, "testjob").
Collector(metric1).
Collector(metric2).
Add(); err != nil {
t.Fatal(err)
}
if lastMethod != "POST" {
t.Error("want method POST for Add, got", lastMethod)
}
if bytes.Compare(lastBody, wantBody) != 0 {
t.Errorf("got body %v, want %v", lastBody, wantBody)
}
if lastPath != "/metrics/job/testjob" {
t.Error("unexpected path:", lastPath)
}
// Push some Collectors with a broken PGW.
if err := New(pgwErr.URL, "testjob").
Collector(metric1).
Collector(metric2).
Push(); err == nil {
t.Error("push to broken Pushgateway succeeded")
} else {
if got, want := err.Error(), "unexpected status code 500 while pushing to "+pgwErr.URL+"/metrics/job/testjob: fake error\n"; got != want {
t.Errorf("got error %q, want %q", got, want)
}
}
// Push some Collectors with invalid grouping or job.
if err := New(pgwOK.URL, "testjob").
Grouping("foo", "bums").
Collector(metric1).
Collector(metric2).
Push(); err == nil {
t.Error("push with grouping contained in metrics succeeded")
}
if err := New(pgwOK.URL, "test/job").
Collector(metric1).
Collector(metric2).
Push(); err == nil {
t.Error("push with invalid job value succeeded")
}
if err := New(pgwOK.URL, "testjob").
Grouping("foobar", "bu/ms").
Collector(metric1).
Collector(metric2).
Push(); err == nil {
t.Error("push with invalid grouping succeeded")
}
if err := New(pgwOK.URL, "testjob").
Grouping("foo-bar", "bums").
Collector(metric1).
Collector(metric2).
Push(); err == nil {
t.Error("push with invalid grouping succeeded")
}
// Push registry, all good.
if err := New(pgwOK.URL, "testjob").
Gatherer(reg).
Push(); err != nil {
t.Fatal(err)
}
if lastMethod != "PUT" {
t.Error("want method PUT for Push, got", lastMethod)
}
if bytes.Compare(lastBody, wantBody) != 0 {
t.Errorf("got body %v, want %v", lastBody, wantBody)
}
// Add registry, all good.
if err := New(pgwOK.URL, "testjob").
Grouping("a", "x").
Grouping("b", "y").
Gatherer(reg).
Add(); err != nil {
t.Fatal(err)
}
if lastMethod != "POST" {
t.Error("want method POST for Add, got", lastMethod)
}
if bytes.Compare(lastBody, wantBody) != 0 {
t.Errorf("got body %v, want %v", lastBody, wantBody)
}
if lastPath != "/metrics/job/testjob/a/x/b/y" && lastPath != "/metrics/job/testjob/b/y/a/x" {
t.Error("unexpected path:", lastPath)
}
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"bytes"
"errors"
"fmt"
"os"
"runtime"
"sort"
"sync"
"unicode/utf8"
"github.com/golang/protobuf/proto"
dto "github.com/prometheus/client_model/go"
)
const (
// Capacity for the channel to collect metrics and descriptors.
capMetricChan = 1000
capDescChan = 10
)
// DefaultRegisterer and DefaultGatherer are the implementations of the
// Registerer and Gatherer interface a number of convenience functions in this
// package act on. Initially, both variables point to the same Registry, which
// has a process collector (currently on Linux only, see NewProcessCollector)
// and a Go collector (see NewGoCollector, in particular the note about
// stop-the-world implication with Go versions older than 1.9) already
// registered. This approach to keep default instances as global state mirrors
// the approach of other packages in the Go standard library. Note that there
// are caveats. Change the variables with caution and only if you understand the
// consequences. Users who want to avoid global state altogether should not use
// the convenience functions and act on custom instances instead.
var (
defaultRegistry = NewRegistry()
DefaultRegisterer Registerer = defaultRegistry
DefaultGatherer Gatherer = defaultRegistry
)
func init() {
MustRegister(NewProcessCollector(os.Getpid(), ""))
MustRegister(NewGoCollector())
}
// NewRegistry creates a new vanilla Registry without any Collectors
// pre-registered.
func NewRegistry() *Registry {
return &Registry{
collectorsByID: map[uint64]Collector{},
descIDs: map[uint64]struct{}{},
dimHashesByName: map[string]uint64{},
}
}
// NewPedanticRegistry returns a registry that checks during collection if each
// collected Metric is consistent with its reported Desc, and if the Desc has
// actually been registered with the registry.
//
// Usually, a Registry will be happy as long as the union of all collected
// Metrics is consistent and valid even if some metrics are not consistent with
// their own Desc or a Desc provided by their registered Collector. Well-behaved
// Collectors and Metrics will only provide consistent Descs. This Registry is
// useful to test the implementation of Collectors and Metrics.
func NewPedanticRegistry() *Registry {
r := NewRegistry()
r.pedanticChecksEnabled = true
return r
}
// Registerer is the interface for the part of a registry in charge of
// registering and unregistering. Users of custom registries should use
// Registerer as type for registration purposes (rather than the Registry type
// directly). In that way, they are free to use custom Registerer implementation
// (e.g. for testing purposes).
type Registerer interface {
// Register registers a new Collector to be included in metrics
// collection. It returns an error if the descriptors provided by the
// Collector are invalid or if they — in combination with descriptors of
// already registered Collectors — do not fulfill the consistency and
// uniqueness criteria described in the documentation of metric.Desc.
//
// If the provided Collector is equal to a Collector already registered
// (which includes the case of re-registering the same Collector), the
// returned error is an instance of AlreadyRegisteredError, which
// contains the previously registered Collector.
//
// It is in general not safe to register the same Collector multiple
// times concurrently.
Register(Collector) error
// MustRegister works like Register but registers any number of
// Collectors and panics upon the first registration that causes an
// error.
MustRegister(...Collector)
// Unregister unregisters the Collector that equals the Collector passed
// in as an argument. (Two Collectors are considered equal if their
// Describe method yields the same set of descriptors.) The function
// returns whether a Collector was unregistered.
//
// Note that even after unregistering, it will not be possible to
// register a new Collector that is inconsistent with the unregistered
// Collector, e.g. a Collector collecting metrics with the same name but
// a different help string. The rationale here is that the same registry
// instance must only collect consistent metrics throughout its
// lifetime.
Unregister(Collector) bool
}
// Gatherer is the interface for the part of a registry in charge of gathering
// the collected metrics into a number of MetricFamilies. The Gatherer interface
// comes with the same general implication as described for the Registerer
// interface.
type Gatherer interface {
// Gather calls the Collect method of the registered Collectors and then
// gathers the collected metrics into a lexicographically sorted slice
// of MetricFamily protobufs. Even if an error occurs, Gather attempts
// to gather as many metrics as possible. Hence, if a non-nil error is
// returned, the returned MetricFamily slice could be nil (in case of a
// fatal error that prevented any meaningful metric collection) or
// contain a number of MetricFamily protobufs, some of which might be
// incomplete, and some might be missing altogether. The returned error
// (which might be a MultiError) explains the details. In scenarios
// where complete collection is critical, the returned MetricFamily
// protobufs should be disregarded if the returned error is non-nil.
Gather() ([]*dto.MetricFamily, error)
}
// Register registers the provided Collector with the DefaultRegisterer.
//
// Register is a shortcut for DefaultRegisterer.Register(c). See there for more
// details.
func Register(c Collector) error {
return DefaultRegisterer.Register(c)
}
// MustRegister registers the provided Collectors with the DefaultRegisterer and
// panics if any error occurs.
//
// MustRegister is a shortcut for DefaultRegisterer.MustRegister(cs...). See
// there for more details.
func MustRegister(cs ...Collector) {
DefaultRegisterer.MustRegister(cs...)
}
// Unregister removes the registration of the provided Collector from the
// DefaultRegisterer.
//
// Unregister is a shortcut for DefaultRegisterer.Unregister(c). See there for
// more details.
func Unregister(c Collector) bool {
return DefaultRegisterer.Unregister(c)
}
// GathererFunc turns a function into a Gatherer.
type GathererFunc func() ([]*dto.MetricFamily, error)
// Gather implements Gatherer.
func (gf GathererFunc) Gather() ([]*dto.MetricFamily, error) {
return gf()
}
// AlreadyRegisteredError is returned by the Register method if the Collector to
// be registered has already been registered before, or a different Collector
// that collects the same metrics has been registered before. Registration fails
// in that case, but you can detect from the kind of error what has
// happened. The error contains fields for the existing Collector and the
// (rejected) new Collector that equals the existing one. This can be used to
// find out if an equal Collector has been registered before and switch over to
// using the old one, as demonstrated in the example.
type AlreadyRegisteredError struct {
ExistingCollector, NewCollector Collector
}
func (err AlreadyRegisteredError) Error() string {
return "duplicate metrics collector registration attempted"
}
// MultiError is a slice of errors implementing the error interface. It is used
// by a Gatherer to report multiple errors during MetricFamily gathering.
type MultiError []error
func (errs MultiError) Error() string {
if len(errs) == 0 {
return ""
}
buf := &bytes.Buffer{}
fmt.Fprintf(buf, "%d error(s) occurred:", len(errs))
for _, err := range errs {
fmt.Fprintf(buf, "\n* %s", err)
}
return buf.String()
}
// Append appends the provided error if it is not nil.
func (errs *MultiError) Append(err error) {
if err != nil {
*errs = append(*errs, err)
}
}
// MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only
// contained error as error if len(errs is 1). In all other cases, it returns
// the MultiError directly. This is helpful for returning a MultiError in a way
// that only uses the MultiError if needed.
func (errs MultiError) MaybeUnwrap() error {
switch len(errs) {
case 0:
return nil
case 1:
return errs[0]
default:
return errs
}
}
// Registry registers Prometheus collectors, collects their metrics, and gathers
// them into MetricFamilies for exposition. It implements both Registerer and
// Gatherer. The zero value is not usable. Create instances with NewRegistry or
// NewPedanticRegistry.
type Registry struct {
mtx sync.RWMutex
collectorsByID map[uint64]Collector // ID is a hash of the descIDs.
descIDs map[uint64]struct{}
dimHashesByName map[string]uint64
pedanticChecksEnabled bool
}
// Register implements Registerer.
func (r *Registry) Register(c Collector) error {
var (
descChan = make(chan *Desc, capDescChan)
newDescIDs = map[uint64]struct{}{}
newDimHashesByName = map[string]uint64{}
collectorID uint64 // Just a sum of all desc IDs.
duplicateDescErr error
)
go func() {
c.Describe(descChan)
close(descChan)
}()
r.mtx.Lock()
defer r.mtx.Unlock()
// Conduct various tests...
for desc := range descChan {
// Is the descriptor valid at all?
if desc.err != nil {
return fmt.Errorf("descriptor %s is invalid: %s", desc, desc.err)
}
// Is the descID unique?
// (In other words: Is the fqName + constLabel combination unique?)
if _, exists := r.descIDs[desc.id]; exists {
duplicateDescErr = fmt.Errorf("descriptor %s already exists with the same fully-qualified name and const label values", desc)
}
// If it is not a duplicate desc in this collector, add it to
// the collectorID. (We allow duplicate descs within the same
// collector, but their existence must be a no-op.)
if _, exists := newDescIDs[desc.id]; !exists {
newDescIDs[desc.id] = struct{}{}
collectorID += desc.id
}
// Are all the label names and the help string consistent with
// previous descriptors of the same name?
// First check existing descriptors...
if dimHash, exists := r.dimHashesByName[desc.fqName]; exists {
if dimHash != desc.dimHash {
return fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc)
}
} else {
// ...then check the new descriptors already seen.
if dimHash, exists := newDimHashesByName[desc.fqName]; exists {
if dimHash != desc.dimHash {
return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc)
}
} else {
newDimHashesByName[desc.fqName] = desc.dimHash
}
}
}
// Did anything happen at all?
if len(newDescIDs) == 0 {
return errors.New("collector has no descriptors")
}
if existing, exists := r.collectorsByID[collectorID]; exists {
return AlreadyRegisteredError{
ExistingCollector: existing,
NewCollector: c,
}
}
// If the collectorID is new, but at least one of the descs existed
// before, we are in trouble.
if duplicateDescErr != nil {
return duplicateDescErr
}
// Only after all tests have passed, actually register.
r.collectorsByID[collectorID] = c
for hash := range newDescIDs {
r.descIDs[hash] = struct{}{}
}
for name, dimHash := range newDimHashesByName {
r.dimHashesByName[name] = dimHash
}
return nil
}
// Unregister implements Registerer.
func (r *Registry) Unregister(c Collector) bool {
var (
descChan = make(chan *Desc, capDescChan)
descIDs = map[uint64]struct{}{}
collectorID uint64 // Just a sum of the desc IDs.
)
go func() {
c.Describe(descChan)
close(descChan)
}()
for desc := range descChan {
if _, exists := descIDs[desc.id]; !exists {
collectorID += desc.id
descIDs[desc.id] = struct{}{}
}
}
r.mtx.RLock()
if _, exists := r.collectorsByID[collectorID]; !exists {
r.mtx.RUnlock()
return false
}
r.mtx.RUnlock()
r.mtx.Lock()
defer r.mtx.Unlock()
delete(r.collectorsByID, collectorID)
for id := range descIDs {
delete(r.descIDs, id)
}
// dimHashesByName is left untouched as those must be consistent
// throughout the lifetime of a program.
return true
}
// MustRegister implements Registerer.
func (r *Registry) MustRegister(cs ...Collector) {
for _, c := range cs {
if err := r.Register(c); err != nil {
panic(err)
}
}
}
// Gather implements Gatherer.
func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
var (
metricChan = make(chan Metric, capMetricChan)
metricHashes = map[uint64]struct{}{}
dimHashes = map[string]uint64{}
wg sync.WaitGroup
errs MultiError // The collected errors to return in the end.
registeredDescIDs map[uint64]struct{} // Only used for pedantic checks
)
r.mtx.RLock()
goroutineBudget := len(r.collectorsByID)
metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName))
collectors := make(chan Collector, len(r.collectorsByID))
for _, collector := range r.collectorsByID {
collectors <- collector
}
// In case pedantic checks are enabled, we have to copy the map before
// giving up the RLock.
if r.pedanticChecksEnabled {
registeredDescIDs = make(map[uint64]struct{}, len(r.descIDs))
for id := range r.descIDs {
registeredDescIDs[id] = struct{}{}
}
}
r.mtx.RUnlock()
wg.Add(goroutineBudget)
collectWorker := func() {
for {
select {
case collector := <-collectors:
collector.Collect(metricChan)
wg.Done()
default:
return
}
}
}
// Start the first worker now to make sure at least one is running.
go collectWorker()
goroutineBudget--
// Close the metricChan once all collectors are collected.
go func() {
wg.Wait()
close(metricChan)
}()
// Drain metricChan in case of premature return.
defer func() {
for range metricChan {
}
}()
collectLoop:
for {
select {
case metric, ok := <-metricChan:
if !ok {
// metricChan is closed, we are done.
break collectLoop
}
errs.Append(processMetric(
metric, metricFamiliesByName,
metricHashes, dimHashes,
registeredDescIDs,
))
default:
if goroutineBudget <= 0 || len(collectors) == 0 {
// All collectors are already being worked on or
// we have already as many goroutines started as
// there are collectors. Just process metrics
// from now on.
for metric := range metricChan {
errs.Append(processMetric(
metric, metricFamiliesByName,
metricHashes, dimHashes,
registeredDescIDs,
))
}
break collectLoop
}
// Start more workers.
go collectWorker()
goroutineBudget--
runtime.Gosched()
}
}
return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
}
// processMetric is an internal helper method only used by the Gather method.
func processMetric(
metric Metric,
metricFamiliesByName map[string]*dto.MetricFamily,
metricHashes map[uint64]struct{},
dimHashes map[string]uint64,
registeredDescIDs map[uint64]struct{},
) error {
desc := metric.Desc()
dtoMetric := &dto.Metric{}
if err := metric.Write(dtoMetric); err != nil {
return fmt.Errorf("error collecting metric %v: %s", desc, err)
}
metricFamily, ok := metricFamiliesByName[desc.fqName]
if ok {
if metricFamily.GetHelp() != desc.help {
return fmt.Errorf(
"collected metric %s %s has help %q but should have %q",
desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(),
)
}
// TODO(beorn7): Simplify switch once Desc has type.
switch metricFamily.GetType() {
case dto.MetricType_COUNTER:
if dtoMetric.Counter == nil {
return fmt.Errorf(
"collected metric %s %s should be a Counter",
desc.fqName, dtoMetric,
)
}
case dto.MetricType_GAUGE:
if dtoMetric.Gauge == nil {
return fmt.Errorf(
"collected metric %s %s should be a Gauge",
desc.fqName, dtoMetric,
)
}
case dto.MetricType_SUMMARY:
if dtoMetric.Summary == nil {
return fmt.Errorf(
"collected metric %s %s should be a Summary",
desc.fqName, dtoMetric,
)
}
case dto.MetricType_UNTYPED:
if dtoMetric.Untyped == nil {
return fmt.Errorf(
"collected metric %s %s should be Untyped",
desc.fqName, dtoMetric,
)
}
case dto.MetricType_HISTOGRAM:
if dtoMetric.Histogram == nil {
return fmt.Errorf(
"collected metric %s %s should be a Histogram",
desc.fqName, dtoMetric,
)
}
default:
panic("encountered MetricFamily with invalid type")
}
} else {
metricFamily = &dto.MetricFamily{}
metricFamily.Name = proto.String(desc.fqName)
metricFamily.Help = proto.String(desc.help)
// TODO(beorn7): Simplify switch once Desc has type.
switch {
case dtoMetric.Gauge != nil:
metricFamily.Type = dto.MetricType_GAUGE.Enum()
case dtoMetric.Counter != nil:
metricFamily.Type = dto.MetricType_COUNTER.Enum()
case dtoMetric.Summary != nil:
metricFamily.Type = dto.MetricType_SUMMARY.Enum()
case dtoMetric.Untyped != nil:
metricFamily.Type = dto.MetricType_UNTYPED.Enum()
case dtoMetric.Histogram != nil:
metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
default:
return fmt.Errorf("empty metric collected: %s", dtoMetric)
}
metricFamiliesByName[desc.fqName] = metricFamily
}
if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes, dimHashes); err != nil {
return err
}
if registeredDescIDs != nil {
// Is the desc registered at all?
if _, exist := registeredDescIDs[desc.id]; !exist {
return fmt.Errorf(
"collected metric %s %s with unregistered descriptor %s",
metricFamily.GetName(), dtoMetric, desc,
)
}
if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil {
return err
}
}
metricFamily.Metric = append(metricFamily.Metric, dtoMetric)
return nil
}
// Gatherers is a slice of Gatherer instances that implements the Gatherer
// interface itself. Its Gather method calls Gather on all Gatherers in the
// slice in order and returns the merged results. Errors returned from the
// Gather calles are all returned in a flattened MultiError. Duplicate and
// inconsistent Metrics are skipped (first occurrence in slice order wins) and
// reported in the returned error.
//
// Gatherers can be used to merge the Gather results from multiple
// Registries. It also provides a way to directly inject existing MetricFamily
// protobufs into the gathering by creating a custom Gatherer with a Gather
// method that simply returns the existing MetricFamily protobufs. Note that no
// registration is involved (in contrast to Collector registration), so
// obviously registration-time checks cannot happen. Any inconsistencies between
// the gathered MetricFamilies are reported as errors by the Gather method, and
// inconsistent Metrics are dropped. Invalid parts of the MetricFamilies
// (e.g. syntactically invalid metric or label names) will go undetected.
type Gatherers []Gatherer
// Gather implements Gatherer.
func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) {
var (
metricFamiliesByName = map[string]*dto.MetricFamily{}
metricHashes = map[uint64]struct{}{}
dimHashes = map[string]uint64{}
errs MultiError // The collected errors to return in the end.
)
for i, g := range gs {
mfs, err := g.Gather()
if err != nil {
if multiErr, ok := err.(MultiError); ok {
for _, err := range multiErr {
errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
}
} else {
errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
}
}
for _, mf := range mfs {
existingMF, exists := metricFamiliesByName[mf.GetName()]
if exists {
if existingMF.GetHelp() != mf.GetHelp() {
errs = append(errs, fmt.Errorf(
"gathered metric family %s has help %q but should have %q",
mf.GetName(), mf.GetHelp(), existingMF.GetHelp(),
))
continue
}
if existingMF.GetType() != mf.GetType() {
errs = append(errs, fmt.Errorf(
"gathered metric family %s has type %s but should have %s",
mf.GetName(), mf.GetType(), existingMF.GetType(),
))
continue
}
} else {
existingMF = &dto.MetricFamily{}
existingMF.Name = mf.Name
existingMF.Help = mf.Help
existingMF.Type = mf.Type
metricFamiliesByName[mf.GetName()] = existingMF
}
for _, m := range mf.Metric {
if err := checkMetricConsistency(existingMF, m, metricHashes, dimHashes); err != nil {
errs = append(errs, err)
continue
}
existingMF.Metric = append(existingMF.Metric, m)
}
}
}
return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
}
// metricSorter is a sortable slice of *dto.Metric.
type metricSorter []*dto.Metric
func (s metricSorter) Len() int {
return len(s)
}
func (s metricSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s metricSorter) Less(i, j int) bool {
if len(s[i].Label) != len(s[j].Label) {
// This should not happen. The metrics are
// inconsistent. However, we have to deal with the fact, as
// people might use custom collectors or metric family injection
// to create inconsistent metrics. So let's simply compare the
// number of labels in this case. That will still yield
// reproducible sorting.
return len(s[i].Label) < len(s[j].Label)
}
for n, lp := range s[i].Label {
vi := lp.GetValue()
vj := s[j].Label[n].GetValue()
if vi != vj {
return vi < vj
}
}
// We should never arrive here. Multiple metrics with the same
// label set in the same scrape will lead to undefined ingestion
// behavior. However, as above, we have to provide stable sorting
// here, even for inconsistent metrics. So sort equal metrics
// by their timestamp, with missing timestamps (implying "now")
// coming last.
if s[i].TimestampMs == nil {
return false
}
if s[j].TimestampMs == nil {
return true
}
return s[i].GetTimestampMs() < s[j].GetTimestampMs()
}
// normalizeMetricFamilies returns a MetricFamily slice with empty
// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
// the slice, with the contained Metrics sorted within each MetricFamily.
func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
for _, mf := range metricFamiliesByName {
sort.Sort(metricSorter(mf.Metric))
}
names := make([]string, 0, len(metricFamiliesByName))
for name, mf := range metricFamiliesByName {
if len(mf.Metric) > 0 {
names = append(names, name)
}
}
sort.Strings(names)
result := make([]*dto.MetricFamily, 0, len(names))
for _, name := range names {
result = append(result, metricFamiliesByName[name])
}
return result
}
// checkMetricConsistency checks if the provided Metric is consistent with the
// provided MetricFamily. It also hashed the Metric labels and the MetricFamily
// name. If the resulting hash is already in the provided metricHashes, an error
// is returned. If not, it is added to metricHashes. The provided dimHashes maps
// MetricFamily names to their dimHash (hashed sorted label names). If dimHashes
// doesn't yet contain a hash for the provided MetricFamily, it is
// added. Otherwise, an error is returned if the existing dimHashes in not equal
// the calculated dimHash.
func checkMetricConsistency(
metricFamily *dto.MetricFamily,
dtoMetric *dto.Metric,
metricHashes map[uint64]struct{},
dimHashes map[string]uint64,
) error {
// Type consistency with metric family.
if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil ||
metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil ||
metricFamily.GetType() == dto.MetricType_SUMMARY && dtoMetric.Summary == nil ||
metricFamily.GetType() == dto.MetricType_HISTOGRAM && dtoMetric.Histogram == nil ||
metricFamily.GetType() == dto.MetricType_UNTYPED && dtoMetric.Untyped == nil {
return fmt.Errorf(
"collected metric %s %s is not a %s",
metricFamily.GetName(), dtoMetric, metricFamily.GetType(),
)
}
for _, labelPair := range dtoMetric.GetLabel() {
if !utf8.ValidString(*labelPair.Value) {
return fmt.Errorf("collected metric's label %s is not utf8: %#v", *labelPair.Name, *labelPair.Value)
}
}
// Is the metric unique (i.e. no other metric with the same name and the same label values)?
h := hashNew()
h = hashAdd(h, metricFamily.GetName())
h = hashAddByte(h, separatorByte)
dh := hashNew()
// Make sure label pairs are sorted. We depend on it for the consistency
// check.
sort.Sort(LabelPairSorter(dtoMetric.Label))
for _, lp := range dtoMetric.Label {
h = hashAdd(h, lp.GetValue())
h = hashAddByte(h, separatorByte)
dh = hashAdd(dh, lp.GetName())
dh = hashAddByte(dh, separatorByte)
}
if _, exists := metricHashes[h]; exists {
return fmt.Errorf(
"collected metric %s %s was collected before with the same name and label values",
metricFamily.GetName(), dtoMetric,
)
}
if dimHash, ok := dimHashes[metricFamily.GetName()]; ok {
if dimHash != dh {
return fmt.Errorf(
"collected metric %s %s has label dimensions inconsistent with previously collected metrics in the same metric family",
metricFamily.GetName(), dtoMetric,
)
}
} else {
dimHashes[metricFamily.GetName()] = dh
}
metricHashes[h] = struct{}{}
return nil
}
func checkDescConsistency(
metricFamily *dto.MetricFamily,
dtoMetric *dto.Metric,
desc *Desc,
) error {
// Desc help consistency with metric family help.
if metricFamily.GetHelp() != desc.help {
return fmt.Errorf(
"collected metric %s %s has help %q but should have %q",
metricFamily.GetName(), dtoMetric, metricFamily.GetHelp(), desc.help,
)
}
// Is the desc consistent with the content of the metric?
lpsFromDesc := make([]*dto.LabelPair, 0, len(dtoMetric.Label))
lpsFromDesc = append(lpsFromDesc, desc.constLabelPairs...)
for _, l := range desc.variableLabels {
lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{
Name: proto.String(l),
})
}
if len(lpsFromDesc) != len(dtoMetric.Label) {
return fmt.Errorf(
"labels in collected metric %s %s are inconsistent with descriptor %s",
metricFamily.GetName(), dtoMetric, desc,
)
}
sort.Sort(LabelPairSorter(lpsFromDesc))
for i, lpFromDesc := range lpsFromDesc {
lpFromMetric := dtoMetric.Label[i]
if lpFromDesc.GetName() != lpFromMetric.GetName() ||
lpFromDesc.Value != nil && lpFromDesc.GetValue() != lpFromMetric.GetValue() {
return fmt.Errorf(
"labels in collected metric %s %s are inconsistent with descriptor %s",
metricFamily.GetName(), dtoMetric, desc,
)
}
}
return nil
}

View File

@ -0,0 +1,590 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Copyright (c) 2013, The Prometheus Authors
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be found
// in the LICENSE file.
package prometheus_test
import (
"bytes"
"net/http"
"net/http/httptest"
"testing"
dto "github.com/prometheus/client_model/go"
"github.com/golang/protobuf/proto"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
func testHandler(t testing.TB) {
metricVec := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "name",
Help: "docstring",
ConstLabels: prometheus.Labels{"constname": "constvalue"},
},
[]string{"labelname"},
)
metricVec.WithLabelValues("val1").Inc()
metricVec.WithLabelValues("val2").Inc()
externalMetricFamily := &dto.MetricFamily{
Name: proto.String("externalname"),
Help: proto.String("externaldocstring"),
Type: dto.MetricType_COUNTER.Enum(),
Metric: []*dto.Metric{
{
Label: []*dto.LabelPair{
{
Name: proto.String("externalconstname"),
Value: proto.String("externalconstvalue"),
},
{
Name: proto.String("externallabelname"),
Value: proto.String("externalval1"),
},
},
Counter: &dto.Counter{
Value: proto.Float64(1),
},
},
},
}
externalBuf := &bytes.Buffer{}
enc := expfmt.NewEncoder(externalBuf, expfmt.FmtProtoDelim)
if err := enc.Encode(externalMetricFamily); err != nil {
t.Fatal(err)
}
externalMetricFamilyAsBytes := externalBuf.Bytes()
externalMetricFamilyAsText := []byte(`# HELP externalname externaldocstring
# TYPE externalname counter
externalname{externalconstname="externalconstvalue",externallabelname="externalval1"} 1
`)
externalMetricFamilyAsProtoText := []byte(`name: "externalname"
help: "externaldocstring"
type: COUNTER
metric: <
label: <
name: "externalconstname"
value: "externalconstvalue"
>
label: <
name: "externallabelname"
value: "externalval1"
>
counter: <
value: 1
>
>
`)
externalMetricFamilyAsProtoCompactText := []byte(`name:"externalname" help:"externaldocstring" type:COUNTER metric:<label:<name:"externalconstname" value:"externalconstvalue" > label:<name:"externallabelname" value:"externalval1" > counter:<value:1 > >
`)
expectedMetricFamily := &dto.MetricFamily{
Name: proto.String("name"),
Help: proto.String("docstring"),
Type: dto.MetricType_COUNTER.Enum(),
Metric: []*dto.Metric{
{
Label: []*dto.LabelPair{
{
Name: proto.String("constname"),
Value: proto.String("constvalue"),
},
{
Name: proto.String("labelname"),
Value: proto.String("val1"),
},
},
Counter: &dto.Counter{
Value: proto.Float64(1),
},
},
{
Label: []*dto.LabelPair{
{
Name: proto.String("constname"),
Value: proto.String("constvalue"),
},
{
Name: proto.String("labelname"),
Value: proto.String("val2"),
},
},
Counter: &dto.Counter{
Value: proto.Float64(1),
},
},
},
}
buf := &bytes.Buffer{}
enc = expfmt.NewEncoder(buf, expfmt.FmtProtoDelim)
if err := enc.Encode(expectedMetricFamily); err != nil {
t.Fatal(err)
}
expectedMetricFamilyAsBytes := buf.Bytes()
expectedMetricFamilyAsText := []byte(`# HELP name docstring
# TYPE name counter
name{constname="constvalue",labelname="val1"} 1
name{constname="constvalue",labelname="val2"} 1
`)
expectedMetricFamilyAsProtoText := []byte(`name: "name"
help: "docstring"
type: COUNTER
metric: <
label: <
name: "constname"
value: "constvalue"
>
label: <
name: "labelname"
value: "val1"
>
counter: <
value: 1
>
>
metric: <
label: <
name: "constname"
value: "constvalue"
>
label: <
name: "labelname"
value: "val2"
>
counter: <
value: 1
>
>
`)
expectedMetricFamilyAsProtoCompactText := []byte(`name:"name" help:"docstring" type:COUNTER metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"val1" > counter:<value:1 > > metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"val2" > counter:<value:1 > >
`)
externalMetricFamilyWithSameName := &dto.MetricFamily{
Name: proto.String("name"),
Help: proto.String("docstring"),
Type: dto.MetricType_COUNTER.Enum(),
Metric: []*dto.Metric{
{
Label: []*dto.LabelPair{
{
Name: proto.String("constname"),
Value: proto.String("constvalue"),
},
{
Name: proto.String("labelname"),
Value: proto.String("different_val"),
},
},
Counter: &dto.Counter{
Value: proto.Float64(42),
},
},
},
}
expectedMetricFamilyMergedWithExternalAsProtoCompactText := []byte(`name:"name" help:"docstring" type:COUNTER metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"different_val" > counter:<value:42 > > metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"val1" > counter:<value:1 > > metric:<label:<name:"constname" value:"constvalue" > label:<name:"labelname" value:"val2" > counter:<value:1 > >
`)
externalMetricFamilyWithInvalidLabelValue := &dto.MetricFamily{
Name: proto.String("name"),
Help: proto.String("docstring"),
Type: dto.MetricType_COUNTER.Enum(),
Metric: []*dto.Metric{
{
Label: []*dto.LabelPair{
{
Name: proto.String("constname"),
Value: proto.String("\xFF"),
},
{
Name: proto.String("labelname"),
Value: proto.String("different_val"),
},
},
Counter: &dto.Counter{
Value: proto.Float64(42),
},
},
},
}
expectedMetricFamilyInvalidLabelValueAsText := []byte(`An error has occurred during metrics gathering:
collected metric's label constname is not utf8: "\xff"
`)
type output struct {
headers map[string]string
body []byte
}
var scenarios = []struct {
headers map[string]string
out output
collector prometheus.Collector
externalMF []*dto.MetricFamily
}{
{ // 0
headers: map[string]string{
"Accept": "foo/bar;q=0.2, dings/bums;q=0.8",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: []byte{},
},
},
{ // 1
headers: map[string]string{
"Accept": "foo/bar;q=0.2, application/quark;q=0.8",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: []byte{},
},
},
{ // 2
headers: map[string]string{
"Accept": "foo/bar;q=0.2, application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=bla;q=0.8",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: []byte{},
},
},
{ // 3
headers: map[string]string{
"Accept": "text/plain;q=0.2, application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited;q=0.8",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited`,
},
body: []byte{},
},
},
{ // 4
headers: map[string]string{
"Accept": "application/json",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: expectedMetricFamilyAsText,
},
collector: metricVec,
},
{ // 5
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited`,
},
body: expectedMetricFamilyAsBytes,
},
collector: metricVec,
},
{ // 6
headers: map[string]string{
"Accept": "application/json",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: externalMetricFamilyAsText,
},
externalMF: []*dto.MetricFamily{externalMetricFamily},
},
{ // 7
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited`,
},
body: externalMetricFamilyAsBytes,
},
externalMF: []*dto.MetricFamily{externalMetricFamily},
},
{ // 8
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited`,
},
body: bytes.Join(
[][]byte{
externalMetricFamilyAsBytes,
expectedMetricFamilyAsBytes,
},
[]byte{},
),
},
collector: metricVec,
externalMF: []*dto.MetricFamily{externalMetricFamily},
},
{ // 9
headers: map[string]string{
"Accept": "text/plain",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: []byte{},
},
},
{ // 10
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=bla;q=0.2, text/plain;q=0.5",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: expectedMetricFamilyAsText,
},
collector: metricVec,
},
{ // 11
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=bla;q=0.2, text/plain;q=0.5;version=0.0.4",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; version=0.0.4; charset=utf-8`,
},
body: bytes.Join(
[][]byte{
externalMetricFamilyAsText,
expectedMetricFamilyAsText,
},
[]byte{},
),
},
collector: metricVec,
externalMF: []*dto.MetricFamily{externalMetricFamily},
},
{ // 12
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited;q=0.2, text/plain;q=0.5;version=0.0.2",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited`,
},
body: bytes.Join(
[][]byte{
externalMetricFamilyAsBytes,
expectedMetricFamilyAsBytes,
},
[]byte{},
),
},
collector: metricVec,
externalMF: []*dto.MetricFamily{externalMetricFamily},
},
{ // 13
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=text;q=0.5, application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited;q=0.4",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=text`,
},
body: bytes.Join(
[][]byte{
externalMetricFamilyAsProtoText,
expectedMetricFamilyAsProtoText,
},
[]byte{},
),
},
collector: metricVec,
externalMF: []*dto.MetricFamily{externalMetricFamily},
},
{ // 14
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=compact-text",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=compact-text`,
},
body: bytes.Join(
[][]byte{
externalMetricFamilyAsProtoCompactText,
expectedMetricFamilyAsProtoCompactText,
},
[]byte{},
),
},
collector: metricVec,
externalMF: []*dto.MetricFamily{externalMetricFamily},
},
{ // 15
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=compact-text",
},
out: output{
headers: map[string]string{
"Content-Type": `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=compact-text`,
},
body: bytes.Join(
[][]byte{
externalMetricFamilyAsProtoCompactText,
expectedMetricFamilyMergedWithExternalAsProtoCompactText,
},
[]byte{},
),
},
collector: metricVec,
externalMF: []*dto.MetricFamily{
externalMetricFamily,
externalMetricFamilyWithSameName,
},
},
{ // 16
headers: map[string]string{
"Accept": "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=compact-text",
},
out: output{
headers: map[string]string{
"Content-Type": `text/plain; charset=utf-8`,
},
body: expectedMetricFamilyInvalidLabelValueAsText,
},
collector: metricVec,
externalMF: []*dto.MetricFamily{
externalMetricFamily,
externalMetricFamilyWithInvalidLabelValue,
},
},
}
for i, scenario := range scenarios {
registry := prometheus.NewPedanticRegistry()
gatherer := prometheus.Gatherer(registry)
if scenario.externalMF != nil {
gatherer = prometheus.Gatherers{
registry,
prometheus.GathererFunc(func() ([]*dto.MetricFamily, error) {
return scenario.externalMF, nil
}),
}
}
if scenario.collector != nil {
registry.Register(scenario.collector)
}
writer := httptest.NewRecorder()
handler := prometheus.InstrumentHandler("prometheus", promhttp.HandlerFor(gatherer, promhttp.HandlerOpts{}))
request, _ := http.NewRequest("GET", "/", nil)
for key, value := range scenario.headers {
request.Header.Add(key, value)
}
handler(writer, request)
for key, value := range scenario.out.headers {
if writer.HeaderMap.Get(key) != value {
t.Errorf(
"%d. expected %q for header %q, got %q",
i, value, key, writer.Header().Get(key),
)
}
}
if !bytes.Equal(scenario.out.body, writer.Body.Bytes()) {
t.Errorf(
"%d. expected body:\n%s\ngot body:\n%s\n",
i, scenario.out.body, writer.Body.Bytes(),
)
}
}
}
func TestHandler(t *testing.T) {
testHandler(t)
}
func BenchmarkHandler(b *testing.B) {
for i := 0; i < b.N; i++ {
testHandler(b)
}
}
func TestRegisterWithOrGet(t *testing.T) {
// Replace the default registerer just to be sure. This is bad, but this
// whole test will go away once RegisterOrGet is removed.
oldRegisterer := prometheus.DefaultRegisterer
defer func() {
prometheus.DefaultRegisterer = oldRegisterer
}()
prometheus.DefaultRegisterer = prometheus.NewRegistry()
original := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "test",
Help: "help",
},
[]string{"foo", "bar"},
)
equalButNotSame := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "test",
Help: "help",
},
[]string{"foo", "bar"},
)
var err error
if err = prometheus.Register(original); err != nil {
t.Fatal(err)
}
if err = prometheus.Register(equalButNotSame); err == nil {
t.Fatal("expected error when registringe equal collector")
}
if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
if are.ExistingCollector != original {
t.Error("expected original collector but got something else")
}
if are.ExistingCollector == equalButNotSame {
t.Error("expected original callector but got new one")
}
} else {
t.Error("unexpected error:", err)
}
}

View File

@ -0,0 +1,609 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"math"
"sort"
"sync"
"time"
"github.com/beorn7/perks/quantile"
"github.com/golang/protobuf/proto"
dto "github.com/prometheus/client_model/go"
)
// quantileLabel is used for the label that defines the quantile in a
// summary.
const quantileLabel = "quantile"
// A Summary captures individual observations from an event or sample stream and
// summarizes them in a manner similar to traditional summary statistics: 1. sum
// of observations, 2. observation count, 3. rank estimations.
//
// A typical use-case is the observation of request latencies. By default, a
// Summary provides the median, the 90th and the 99th percentile of the latency
// as rank estimations. However, the default behavior will change in the
// upcoming v0.10 of the library. There will be no rank estiamtions at all by
// default. For a sane transition, it is recommended to set the desired rank
// estimations explicitly.
//
// Note that the rank estimations cannot be aggregated in a meaningful way with
// the Prometheus query language (i.e. you cannot average or add them). If you
// need aggregatable quantiles (e.g. you want the 99th percentile latency of all
// queries served across all instances of a service), consider the Histogram
// metric type. See the Prometheus documentation for more details.
//
// To create Summary instances, use NewSummary.
type Summary interface {
Metric
Collector
// Observe adds a single observation to the summary.
Observe(float64)
}
// DefObjectives are the default Summary quantile values.
//
// Deprecated: DefObjectives will not be used as the default objectives in
// v0.10 of the library. The default Summary will have no quantiles then.
var (
DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
errQuantileLabelNotAllowed = fmt.Errorf(
"%q is not allowed as label name in summaries", quantileLabel,
)
)
// Default values for SummaryOpts.
const (
// DefMaxAge is the default duration for which observations stay
// relevant.
DefMaxAge time.Duration = 10 * time.Minute
// DefAgeBuckets is the default number of buckets used to calculate the
// age of observations.
DefAgeBuckets = 5
// DefBufCap is the standard buffer size for collecting Summary observations.
DefBufCap = 500
)
// SummaryOpts bundles the options for creating a Summary metric. It is
// mandatory to set Name and Help to a non-empty string. While all other fields
// are optional and can safely be left at their zero value, it is recommended to
// explicitly set the Objectives field to the desired value as the default value
// will change in the upcoming v0.10 of the library.
type SummaryOpts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Summary (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the Summary must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this Summary. Mandatory!
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this metric. Metrics
// with the same fully-qualified name must have the same label names in
// their ConstLabels.
//
// ConstLabels are only used rarely. In particular, do not use them to
// attach the same labels to all your metrics. Those use cases are
// better covered by target labels set by the scraping Prometheus
// server, or by one specific metric (e.g. a build_info or a
// machine_role metric). See also
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
ConstLabels Labels
// Objectives defines the quantile rank estimates with their respective
// absolute error. If Objectives[q] = e, then the value reported for q
// will be the φ-quantile value for some φ between q-e and q+e. The
// default value is DefObjectives. It is used if Objectives is left at
// its zero value (i.e. nil). To create a Summary without Objectives,
// set it to an empty map (i.e. map[float64]float64{}).
//
// Deprecated: Note that the current value of DefObjectives is
// deprecated. It will be replaced by an empty map in v0.10 of the
// library. Please explicitly set Objectives to the desired value.
Objectives map[float64]float64
// MaxAge defines the duration for which an observation stays relevant
// for the summary. Must be positive. The default value is DefMaxAge.
MaxAge time.Duration
// AgeBuckets is the number of buckets used to exclude observations that
// are older than MaxAge from the summary. A higher number has a
// resource penalty, so only increase it if the higher resolution is
// really required. For very high observation rates, you might want to
// reduce the number of age buckets. With only one age bucket, you will
// effectively see a complete reset of the summary each time MaxAge has
// passed. The default value is DefAgeBuckets.
AgeBuckets uint32
// BufCap defines the default sample stream buffer size. The default
// value of DefBufCap should suffice for most uses. If there is a need
// to increase the value, a multiple of 500 is recommended (because that
// is the internal buffer size of the underlying package
// "github.com/bmizerany/perks/quantile").
BufCap uint32
}
// Great fuck-up with the sliding-window decay algorithm... The Merge method of
// perk/quantile is actually not working as advertised - and it might be
// unfixable, as the underlying algorithm is apparently not capable of merging
// summaries in the first place. To avoid using Merge, we are currently adding
// observations to _each_ age bucket, i.e. the effort to add a sample is
// essentially multiplied by the number of age buckets. When rotating age
// buckets, we empty the previous head stream. On scrape time, we simply take
// the quantiles from the head stream (no merging required). Result: More effort
// on observation time, less effort on scrape time, which is exactly the
// opposite of what we try to accomplish, but at least the results are correct.
//
// The quite elegant previous contraption to merge the age buckets efficiently
// on scrape time (see code up commit 6b9530d72ea715f0ba612c0120e6e09fbf1d49d0)
// can't be used anymore.
// NewSummary creates a new Summary based on the provided SummaryOpts.
func NewSummary(opts SummaryOpts) Summary {
return newSummary(
NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
),
opts,
)
}
func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
if len(desc.variableLabels) != len(labelValues) {
panic(errInconsistentCardinality)
}
for _, n := range desc.variableLabels {
if n == quantileLabel {
panic(errQuantileLabelNotAllowed)
}
}
for _, lp := range desc.constLabelPairs {
if lp.GetName() == quantileLabel {
panic(errQuantileLabelNotAllowed)
}
}
if opts.Objectives == nil {
opts.Objectives = DefObjectives
}
if opts.MaxAge < 0 {
panic(fmt.Errorf("illegal max age MaxAge=%v", opts.MaxAge))
}
if opts.MaxAge == 0 {
opts.MaxAge = DefMaxAge
}
if opts.AgeBuckets == 0 {
opts.AgeBuckets = DefAgeBuckets
}
if opts.BufCap == 0 {
opts.BufCap = DefBufCap
}
s := &summary{
desc: desc,
objectives: opts.Objectives,
sortedObjectives: make([]float64, 0, len(opts.Objectives)),
labelPairs: makeLabelPairs(desc, labelValues),
hotBuf: make([]float64, 0, opts.BufCap),
coldBuf: make([]float64, 0, opts.BufCap),
streamDuration: opts.MaxAge / time.Duration(opts.AgeBuckets),
}
s.headStreamExpTime = time.Now().Add(s.streamDuration)
s.hotBufExpTime = s.headStreamExpTime
for i := uint32(0); i < opts.AgeBuckets; i++ {
s.streams = append(s.streams, s.newStream())
}
s.headStream = s.streams[0]
for qu := range s.objectives {
s.sortedObjectives = append(s.sortedObjectives, qu)
}
sort.Float64s(s.sortedObjectives)
s.init(s) // Init self-collection.
return s
}
type summary struct {
selfCollector
bufMtx sync.Mutex // Protects hotBuf and hotBufExpTime.
mtx sync.Mutex // Protects every other moving part.
// Lock bufMtx before mtx if both are needed.
desc *Desc
objectives map[float64]float64
sortedObjectives []float64
labelPairs []*dto.LabelPair
sum float64
cnt uint64
hotBuf, coldBuf []float64
streams []*quantile.Stream
streamDuration time.Duration
headStream *quantile.Stream
headStreamIdx int
headStreamExpTime, hotBufExpTime time.Time
}
func (s *summary) Desc() *Desc {
return s.desc
}
func (s *summary) Observe(v float64) {
s.bufMtx.Lock()
defer s.bufMtx.Unlock()
now := time.Now()
if now.After(s.hotBufExpTime) {
s.asyncFlush(now)
}
s.hotBuf = append(s.hotBuf, v)
if len(s.hotBuf) == cap(s.hotBuf) {
s.asyncFlush(now)
}
}
func (s *summary) Write(out *dto.Metric) error {
sum := &dto.Summary{}
qs := make([]*dto.Quantile, 0, len(s.objectives))
s.bufMtx.Lock()
s.mtx.Lock()
// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
s.swapBufs(time.Now())
s.bufMtx.Unlock()
s.flushColdBuf()
sum.SampleCount = proto.Uint64(s.cnt)
sum.SampleSum = proto.Float64(s.sum)
for _, rank := range s.sortedObjectives {
var q float64
if s.headStream.Count() == 0 {
q = math.NaN()
} else {
q = s.headStream.Query(rank)
}
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
s.mtx.Unlock()
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
func (s *summary) newStream() *quantile.Stream {
return quantile.NewTargeted(s.objectives)
}
// asyncFlush needs bufMtx locked.
func (s *summary) asyncFlush(now time.Time) {
s.mtx.Lock()
s.swapBufs(now)
// Unblock the original goroutine that was responsible for the mutation
// that triggered the compaction. But hold onto the global non-buffer
// state mutex until the operation finishes.
go func() {
s.flushColdBuf()
s.mtx.Unlock()
}()
}
// rotateStreams needs mtx AND bufMtx locked.
func (s *summary) maybeRotateStreams() {
for !s.hotBufExpTime.Equal(s.headStreamExpTime) {
s.headStream.Reset()
s.headStreamIdx++
if s.headStreamIdx >= len(s.streams) {
s.headStreamIdx = 0
}
s.headStream = s.streams[s.headStreamIdx]
s.headStreamExpTime = s.headStreamExpTime.Add(s.streamDuration)
}
}
// flushColdBuf needs mtx locked.
func (s *summary) flushColdBuf() {
for _, v := range s.coldBuf {
for _, stream := range s.streams {
stream.Insert(v)
}
s.cnt++
s.sum += v
}
s.coldBuf = s.coldBuf[0:0]
s.maybeRotateStreams()
}
// swapBufs needs mtx AND bufMtx locked, coldBuf must be empty.
func (s *summary) swapBufs(now time.Time) {
if len(s.coldBuf) != 0 {
panic("coldBuf is not empty")
}
s.hotBuf, s.coldBuf = s.coldBuf, s.hotBuf
// hotBuf is now empty and gets new expiration set.
for now.After(s.hotBufExpTime) {
s.hotBufExpTime = s.hotBufExpTime.Add(s.streamDuration)
}
}
type quantSort []*dto.Quantile
func (s quantSort) Len() int {
return len(s)
}
func (s quantSort) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s quantSort) Less(i, j int) bool {
return s[i].GetQuantile() < s[j].GetQuantile()
}
// SummaryVec is a Collector that bundles a set of Summaries that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. HTTP request latencies, partitioned by status code and method). Create
// instances with NewSummaryVec.
type SummaryVec struct {
*metricVec
}
// NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
// partitioned by the given label names.
func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &SummaryVec{
metricVec: newMetricVec(desc, func(lvs ...string) Metric {
return newSummary(desc, opts, lvs...)
}),
}
}
// GetMetricWithLabelValues returns the Summary for the given slice of label
// values (same order as the VariableLabels in Desc). If that combination of
// label values is accessed for the first time, a new Summary is created.
//
// It is possible to call this method without using the returned Summary to only
// create the new Summary but leave it at its starting value, a Summary without
// any observations.
//
// Keeping the Summary for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Summary from the SummaryVec. In that case,
// the Summary will still exist, but it will not be exported anymore, even if a
// Summary with the same label values is created later. See also the CounterVec
// example.
//
// An error is returned if the number of label values is not the same as the
// number of VariableLabels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the GaugeVec example.
func (v *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Observer), err
}
return nil, err
}
// GetMetricWith returns the Summary for the given Labels map (the label names
// must match those of the VariableLabels in Desc). If that label map is
// accessed for the first time, a new Summary is created. Implications of
// creating a Summary without using it and keeping the Summary for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Observer), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
// myVec.WithLabelValues("404", "GET").Observe(42.21)
func (v *SummaryVec) WithLabelValues(lvs ...string) Observer {
s, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return s
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
func (v *SummaryVec) With(labels Labels) Observer {
s, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return s
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the SummaryVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *SummaryVec) CurryWith(labels Labels) (ObserverVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &SummaryVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *SummaryVec) MustCurryWith(labels Labels) ObserverVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
type constSummary struct {
desc *Desc
count uint64
sum float64
quantiles map[float64]float64
labelPairs []*dto.LabelPair
}
func (s *constSummary) Desc() *Desc {
return s.desc
}
func (s *constSummary) Write(out *dto.Metric) error {
sum := &dto.Summary{}
qs := make([]*dto.Quantile, 0, len(s.quantiles))
sum.SampleCount = proto.Uint64(s.count)
sum.SampleSum = proto.Float64(s.sum)
for rank, q := range s.quantiles {
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
// NewConstSummary returns a metric representing a Prometheus summary with fixed
// values for the count, sum, and quantiles. As those parameters cannot be
// changed, the returned value does not implement the Summary interface (but
// only the Metric interface). Users of this package will not have much use for
// it in regular operations. However, when implementing custom Collectors, it is
// useful as a throw-away metric that is generated on the fly to send it to
// Prometheus in the Collect method.
//
// quantiles maps ranks to quantile values. For example, a median latency of
// 0.23s and a 99th percentile latency of 0.56s would be expressed as:
// map[float64]float64{0.5: 0.23, 0.99: 0.56}
//
// NewConstSummary returns an error if the length of labelValues is not
// consistent with the variable labels in Desc.
func NewConstSummary(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
labelValues ...string,
) (Metric, error) {
if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
return nil, err
}
return &constSummary{
desc: desc,
count: count,
sum: sum,
quantiles: quantiles,
labelPairs: makeLabelPairs(desc, labelValues),
}, nil
}
// MustNewConstSummary is a version of NewConstSummary that panics where
// NewConstMetric would have returned an error.
func MustNewConstSummary(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
labelValues ...string,
) Metric {
m, err := NewConstSummary(desc, count, sum, quantiles, labelValues...)
if err != nil {
panic(err)
}
return m
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"math"
"math/rand"
"sort"
"sync"
"testing"
"testing/quick"
"time"
dto "github.com/prometheus/client_model/go"
)
func TestSummaryWithDefaultObjectives(t *testing.T) {
reg := NewRegistry()
summaryWithDefaultObjectives := NewSummary(SummaryOpts{
Name: "default_objectives",
Help: "Test help.",
})
if err := reg.Register(summaryWithDefaultObjectives); err != nil {
t.Error(err)
}
m := &dto.Metric{}
if err := summaryWithDefaultObjectives.Write(m); err != nil {
t.Error(err)
}
if len(m.GetSummary().Quantile) != len(DefObjectives) {
t.Error("expected default objectives in summary")
}
}
func TestSummaryWithoutObjectives(t *testing.T) {
reg := NewRegistry()
summaryWithEmptyObjectives := NewSummary(SummaryOpts{
Name: "empty_objectives",
Help: "Test help.",
Objectives: map[float64]float64{},
})
if err := reg.Register(summaryWithEmptyObjectives); err != nil {
t.Error(err)
}
m := &dto.Metric{}
if err := summaryWithEmptyObjectives.Write(m); err != nil {
t.Error(err)
}
if len(m.GetSummary().Quantile) != 0 {
t.Error("expected no objectives in summary")
}
}
func benchmarkSummaryObserve(w int, b *testing.B) {
b.StopTimer()
wg := new(sync.WaitGroup)
wg.Add(w)
g := new(sync.WaitGroup)
g.Add(1)
s := NewSummary(SummaryOpts{})
for i := 0; i < w; i++ {
go func() {
g.Wait()
for i := 0; i < b.N; i++ {
s.Observe(float64(i))
}
wg.Done()
}()
}
b.StartTimer()
g.Done()
wg.Wait()
}
func BenchmarkSummaryObserve1(b *testing.B) {
benchmarkSummaryObserve(1, b)
}
func BenchmarkSummaryObserve2(b *testing.B) {
benchmarkSummaryObserve(2, b)
}
func BenchmarkSummaryObserve4(b *testing.B) {
benchmarkSummaryObserve(4, b)
}
func BenchmarkSummaryObserve8(b *testing.B) {
benchmarkSummaryObserve(8, b)
}
func benchmarkSummaryWrite(w int, b *testing.B) {
b.StopTimer()
wg := new(sync.WaitGroup)
wg.Add(w)
g := new(sync.WaitGroup)
g.Add(1)
s := NewSummary(SummaryOpts{})
for i := 0; i < 1000000; i++ {
s.Observe(float64(i))
}
for j := 0; j < w; j++ {
outs := make([]dto.Metric, b.N)
go func(o []dto.Metric) {
g.Wait()
for i := 0; i < b.N; i++ {
s.Write(&o[i])
}
wg.Done()
}(outs)
}
b.StartTimer()
g.Done()
wg.Wait()
}
func BenchmarkSummaryWrite1(b *testing.B) {
benchmarkSummaryWrite(1, b)
}
func BenchmarkSummaryWrite2(b *testing.B) {
benchmarkSummaryWrite(2, b)
}
func BenchmarkSummaryWrite4(b *testing.B) {
benchmarkSummaryWrite(4, b)
}
func BenchmarkSummaryWrite8(b *testing.B) {
benchmarkSummaryWrite(8, b)
}
func TestSummaryConcurrency(t *testing.T) {
if testing.Short() {
t.Skip("Skipping test in short mode.")
}
rand.Seed(42)
it := func(n uint32) bool {
mutations := int(n%1e4 + 1e4)
concLevel := int(n%5 + 1)
total := mutations * concLevel
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
sum := NewSummary(SummaryOpts{
Name: "test_summary",
Help: "helpless",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
})
allVars := make([]float64, total)
var sampleSum float64
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
for j := 0; j < mutations; j++ {
v := rand.NormFloat64()
vals[j] = v
allVars[i*mutations+j] = v
sampleSum += v
}
go func(vals []float64) {
start.Wait()
for _, v := range vals {
sum.Observe(v)
}
end.Done()
}(vals)
}
sort.Float64s(allVars)
start.Done()
end.Wait()
m := &dto.Metric{}
sum.Write(m)
if got, want := int(*m.Summary.SampleCount), total; got != want {
t.Errorf("got sample count %d, want %d", got, want)
}
if got, want := *m.Summary.SampleSum, sampleSum; math.Abs((got-want)/want) > 0.001 {
t.Errorf("got sample sum %f, want %f", got, want)
}
objectives := make([]float64, 0, len(DefObjectives))
for qu := range DefObjectives {
objectives = append(objectives, qu)
}
sort.Float64s(objectives)
for i, wantQ := range objectives {
ε := DefObjectives[wantQ]
gotQ := *m.Summary.Quantile[i].Quantile
gotV := *m.Summary.Quantile[i].Value
min, max := getBounds(allVars, wantQ, ε)
if gotQ != wantQ {
t.Errorf("got quantile %f, want %f", gotQ, wantQ)
}
if gotV < min || gotV > max {
t.Errorf("got %f for quantile %f, want [%f,%f]", gotV, gotQ, min, max)
}
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Error(err)
}
}
func TestSummaryVecConcurrency(t *testing.T) {
if testing.Short() {
t.Skip("Skipping test in short mode.")
}
rand.Seed(42)
objectives := make([]float64, 0, len(DefObjectives))
for qu := range DefObjectives {
objectives = append(objectives, qu)
}
sort.Float64s(objectives)
it := func(n uint32) bool {
mutations := int(n%1e4 + 1e4)
concLevel := int(n%7 + 1)
vecLength := int(n%3 + 1)
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
sum := NewSummaryVec(
SummaryOpts{
Name: "test_summary",
Help: "helpless",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"label"},
)
allVars := make([][]float64, vecLength)
sampleSums := make([]float64, vecLength)
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
picks := make([]int, mutations)
for j := 0; j < mutations; j++ {
v := rand.NormFloat64()
vals[j] = v
pick := rand.Intn(vecLength)
picks[j] = pick
allVars[pick] = append(allVars[pick], v)
sampleSums[pick] += v
}
go func(vals []float64) {
start.Wait()
for i, v := range vals {
sum.WithLabelValues(string('A' + picks[i])).Observe(v)
}
end.Done()
}(vals)
}
for _, vars := range allVars {
sort.Float64s(vars)
}
start.Done()
end.Wait()
for i := 0; i < vecLength; i++ {
m := &dto.Metric{}
s := sum.WithLabelValues(string('A' + i))
s.(Summary).Write(m)
if got, want := int(*m.Summary.SampleCount), len(allVars[i]); got != want {
t.Errorf("got sample count %d for label %c, want %d", got, 'A'+i, want)
}
if got, want := *m.Summary.SampleSum, sampleSums[i]; math.Abs((got-want)/want) > 0.001 {
t.Errorf("got sample sum %f for label %c, want %f", got, 'A'+i, want)
}
for j, wantQ := range objectives {
ε := DefObjectives[wantQ]
gotQ := *m.Summary.Quantile[j].Quantile
gotV := *m.Summary.Quantile[j].Value
min, max := getBounds(allVars[i], wantQ, ε)
if gotQ != wantQ {
t.Errorf("got quantile %f for label %c, want %f", gotQ, 'A'+i, wantQ)
}
if gotV < min || gotV > max {
t.Errorf("got %f for quantile %f for label %c, want [%f,%f]", gotV, gotQ, 'A'+i, min, max)
}
}
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Error(err)
}
}
func TestSummaryDecay(t *testing.T) {
if testing.Short() {
t.Skip("Skipping test in short mode.")
// More because it depends on timing than because it is particularly long...
}
sum := NewSummary(SummaryOpts{
Name: "test_summary",
Help: "helpless",
MaxAge: 100 * time.Millisecond,
Objectives: map[float64]float64{0.1: 0.001},
AgeBuckets: 10,
})
m := &dto.Metric{}
i := 0
tick := time.NewTicker(time.Millisecond)
for range tick.C {
i++
sum.Observe(float64(i))
if i%10 == 0 {
sum.Write(m)
if got, want := *m.Summary.Quantile[0].Value, math.Max(float64(i)/10, float64(i-90)); math.Abs(got-want) > 20 {
t.Errorf("%d. got %f, want %f", i, got, want)
}
m.Reset()
}
if i >= 1000 {
break
}
}
tick.Stop()
// Wait for MaxAge without observations and make sure quantiles are NaN.
time.Sleep(100 * time.Millisecond)
sum.Write(m)
if got := *m.Summary.Quantile[0].Value; !math.IsNaN(got) {
t.Errorf("got %f, want NaN after expiration", got)
}
}
func getBounds(vars []float64, q, ε float64) (min, max float64) {
// TODO(beorn7): This currently tolerates an error of up to 2*ε. The
// error must be at most ε, but for some reason, it's sometimes slightly
// higher. That's a bug.
n := float64(len(vars))
lower := int((q - 2*ε) * n)
upper := int(math.Ceil((q + 2*ε) * n))
min = vars[0]
if lower > 1 {
min = vars[lower-1]
}
max = vars[len(vars)-1]
if upper < len(vars) {
max = vars[upper-1]
}
return
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import "time"
// Timer is a helper type to time functions. Use NewTimer to create new
// instances.
type Timer struct {
begin time.Time
observer Observer
}
// NewTimer creates a new Timer. The provided Observer is used to observe a
// duration in seconds. Timer is usually used to time a function call in the
// following way:
// func TimeMe() {
// timer := NewTimer(myHistogram)
// defer timer.ObserveDuration()
// // Do actual work.
// }
func NewTimer(o Observer) *Timer {
return &Timer{
begin: time.Now(),
observer: o,
}
}
// ObserveDuration records the duration passed since the Timer was created with
// NewTimer. It calls the Observe method of the Observer provided during
// construction with the duration in seconds as an argument. ObserveDuration is
// usually called with a defer statement.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
func (t *Timer) ObserveDuration() {
if t.observer != nil {
t.observer.Observe(time.Since(t.begin).Seconds())
}
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"testing"
dto "github.com/prometheus/client_model/go"
)
func TestTimerObserve(t *testing.T) {
var (
his = NewHistogram(HistogramOpts{Name: "test_histogram"})
sum = NewSummary(SummaryOpts{Name: "test_summary"})
gauge = NewGauge(GaugeOpts{Name: "test_gauge"})
)
func() {
hisTimer := NewTimer(his)
sumTimer := NewTimer(sum)
gaugeTimer := NewTimer(ObserverFunc(gauge.Set))
defer hisTimer.ObserveDuration()
defer sumTimer.ObserveDuration()
defer gaugeTimer.ObserveDuration()
}()
m := &dto.Metric{}
his.Write(m)
if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for histogram, got %d", want, got)
}
m.Reset()
sum.Write(m)
if want, got := uint64(1), m.GetSummary().GetSampleCount(); want != got {
t.Errorf("want %d observations for summary, got %d", want, got)
}
m.Reset()
gauge.Write(m)
if got := m.GetGauge().GetValue(); got <= 0 {
t.Errorf("want value > 0 for gauge, got %f", got)
}
}
func TestTimerEmpty(t *testing.T) {
emptyTimer := NewTimer(nil)
emptyTimer.ObserveDuration()
// Do nothing, just demonstrate it works without panic.
}
func TestTimerConditionalTiming(t *testing.T) {
var (
his = NewHistogram(HistogramOpts{
Name: "test_histogram",
})
timeMe = true
m = &dto.Metric{}
)
timedFunc := func() {
timer := NewTimer(ObserverFunc(func(v float64) {
if timeMe {
his.Observe(v)
}
}))
defer timer.ObserveDuration()
}
timedFunc() // This will time.
his.Write(m)
if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for histogram, got %d", want, got)
}
timeMe = false
timedFunc() // This will not time again.
m.Reset()
his.Write(m)
if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for histogram, got %d", want, got)
}
}
func TestTimerByOutcome(t *testing.T) {
var (
his = NewHistogramVec(
HistogramOpts{Name: "test_histogram"},
[]string{"outcome"},
)
outcome = "foo"
m = &dto.Metric{}
)
timedFunc := func() {
timer := NewTimer(ObserverFunc(func(v float64) {
his.WithLabelValues(outcome).Observe(v)
}))
defer timer.ObserveDuration()
if outcome == "foo" {
outcome = "bar"
return
}
outcome = "foo"
}
timedFunc()
his.WithLabelValues("foo").(Histogram).Write(m)
if want, got := uint64(0), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for 'foo' histogram, got %d", want, got)
}
m.Reset()
his.WithLabelValues("bar").(Histogram).Write(m)
if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for 'bar' histogram, got %d", want, got)
}
timedFunc()
m.Reset()
his.WithLabelValues("foo").(Histogram).Write(m)
if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for 'foo' histogram, got %d", want, got)
}
m.Reset()
his.WithLabelValues("bar").(Histogram).Write(m)
if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for 'bar' histogram, got %d", want, got)
}
timedFunc()
m.Reset()
his.WithLabelValues("foo").(Histogram).Write(m)
if want, got := uint64(1), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for 'foo' histogram, got %d", want, got)
}
m.Reset()
his.WithLabelValues("bar").(Histogram).Write(m)
if want, got := uint64(2), m.GetHistogram().GetSampleCount(); want != got {
t.Errorf("want %d observations for 'bar' histogram, got %d", want, got)
}
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// UntypedOpts is an alias for Opts. See there for doc comments.
type UntypedOpts Opts
// UntypedFunc works like GaugeFunc but the collected metric is of type
// "Untyped". UntypedFunc is useful to mirror an external metric of unknown
// type.
//
// To create UntypedFunc instances, use NewUntypedFunc.
type UntypedFunc interface {
Metric
Collector
}
// NewUntypedFunc creates a new UntypedFunc based on the provided
// UntypedOpts. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where an UntypedFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe.
func NewUntypedFunc(opts UntypedOpts, function func() float64) UntypedFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), UntypedValue, function)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"sort"
dto "github.com/prometheus/client_model/go"
"github.com/golang/protobuf/proto"
)
// ValueType is an enumeration of metric types that represent a simple value.
type ValueType int
// Possible values for the ValueType enum.
const (
_ ValueType = iota
CounterValue
GaugeValue
UntypedValue
)
// valueFunc is a generic metric for simple values retrieved on collect time
// from a function. It implements Metric and Collector. Its effective type is
// determined by ValueType. This is a low-level building block used by the
// library to back the implementations of CounterFunc, GaugeFunc, and
// UntypedFunc.
type valueFunc struct {
selfCollector
desc *Desc
valType ValueType
function func() float64
labelPairs []*dto.LabelPair
}
// newValueFunc returns a newly allocated valueFunc with the given Desc and
// ValueType. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where a valueFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe.
func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *valueFunc {
result := &valueFunc{
desc: desc,
valType: valueType,
function: function,
labelPairs: makeLabelPairs(desc, nil),
}
result.init(result)
return result
}
func (v *valueFunc) Desc() *Desc {
return v.desc
}
func (v *valueFunc) Write(out *dto.Metric) error {
return populateMetric(v.valType, v.function(), v.labelPairs, out)
}
// NewConstMetric returns a metric with one fixed value that cannot be
// changed. Users of this package will not have much use for it in regular
// operations. However, when implementing custom Collectors, it is useful as a
// throw-away metric that is generated on the fly to send it to Prometheus in
// the Collect method. NewConstMetric returns an error if the length of
// labelValues is not consistent with the variable labels in Desc.
func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
return nil, err
}
return &constMetric{
desc: desc,
valType: valueType,
val: value,
labelPairs: makeLabelPairs(desc, labelValues),
}, nil
}
// MustNewConstMetric is a version of NewConstMetric that panics where
// NewConstMetric would have returned an error.
func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric {
m, err := NewConstMetric(desc, valueType, value, labelValues...)
if err != nil {
panic(err)
}
return m
}
type constMetric struct {
desc *Desc
valType ValueType
val float64
labelPairs []*dto.LabelPair
}
func (m *constMetric) Desc() *Desc {
return m.desc
}
func (m *constMetric) Write(out *dto.Metric) error {
return populateMetric(m.valType, m.val, m.labelPairs, out)
}
func populateMetric(
t ValueType,
v float64,
labelPairs []*dto.LabelPair,
m *dto.Metric,
) error {
m.Label = labelPairs
switch t {
case CounterValue:
m.Counter = &dto.Counter{Value: proto.Float64(v)}
case GaugeValue:
m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
case UntypedValue:
m.Untyped = &dto.Untyped{Value: proto.Float64(v)}
default:
return fmt.Errorf("encountered unknown type %v", t)
}
return nil
}
func makeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
totalLen := len(desc.variableLabels) + len(desc.constLabelPairs)
if totalLen == 0 {
// Super fast path.
return nil
}
if len(desc.variableLabels) == 0 {
// Moderately fast path.
return desc.constLabelPairs
}
labelPairs := make([]*dto.LabelPair, 0, totalLen)
for i, n := range desc.variableLabels {
labelPairs = append(labelPairs, &dto.LabelPair{
Name: proto.String(n),
Value: proto.String(labelValues[i]),
})
}
labelPairs = append(labelPairs, desc.constLabelPairs...)
sort.Sort(LabelPairSorter(labelPairs))
return labelPairs
}

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package prometheus
import (
"fmt"
"testing"
)
func TestNewConstMetricInvalidLabelValues(t *testing.T) {
testCases := []struct {
desc string
labels Labels
}{
{
desc: "non utf8 label value",
labels: Labels{"a": "\xFF"},
},
{
desc: "not enough label values",
labels: Labels{},
},
{
desc: "too many label values",
labels: Labels{"a": "1", "b": "2"},
},
}
for _, test := range testCases {
metricDesc := NewDesc(
"sample_value",
"sample value",
[]string{"a"},
Labels{},
)
expectPanic(t, func() {
MustNewConstMetric(metricDesc, CounterValue, 0.3, "\xFF")
}, fmt.Sprintf("WithLabelValues: expected panic because: %s", test.desc))
if _, err := NewConstMetric(metricDesc, CounterValue, 0.3, "\xFF"); err == nil {
t.Errorf("NewConstMetric: expected error because: %s", test.desc)
}
}
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"sync"
"github.com/prometheus/common/model"
)
// metricVec is a Collector to bundle metrics of the same name that differ in
// their label values. metricVec is not used directly (and therefore
// unexported). It is used as a building block for implementations of vectors of
// a given metric type, like GaugeVec, CounterVec, SummaryVec, and HistogramVec.
// It also handles label currying. It uses basicMetricVec internally.
type metricVec struct {
*metricMap
curry []curriedLabelValue
// hashAdd and hashAddByte can be replaced for testing collision handling.
hashAdd func(h uint64, s string) uint64
hashAddByte func(h uint64, b byte) uint64
}
// newMetricVec returns an initialized metricVec.
func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *metricVec {
return &metricVec{
metricMap: &metricMap{
metrics: map[uint64][]metricWithLabelValues{},
desc: desc,
newMetric: newMetric,
},
hashAdd: hashAdd,
hashAddByte: hashAddByte,
}
}
// DeleteLabelValues removes the metric where the variable labels are the same
// as those passed in as labels (same order as the VariableLabels in Desc). It
// returns true if a metric was deleted.
//
// It is not an error if the number of label values is not the same as the
// number of VariableLabels in Desc. However, such inconsistent label count can
// never match an actual metric, so the method will always return false in that
// case.
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider Delete(Labels) as an
// alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the CounterVec example.
func (m *metricVec) DeleteLabelValues(lvs ...string) bool {
h, err := m.hashLabelValues(lvs)
if err != nil {
return false
}
return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry)
}
// Delete deletes the metric where the variable labels are the same as those
// passed in as labels. It returns true if a metric was deleted.
//
// It is not an error if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc. However, such inconsistent Labels
// can never match an actual metric, so the method will always return false in
// that case.
//
// This method is used for the same purpose as DeleteLabelValues(...string). See
// there for pros and cons of the two methods.
func (m *metricVec) Delete(labels Labels) bool {
h, err := m.hashLabels(labels)
if err != nil {
return false
}
return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
}
func (m *metricVec) curryWith(labels Labels) (*metricVec, error) {
var (
newCurry []curriedLabelValue
oldCurry = m.curry
iCurry int
)
for i, label := range m.desc.variableLabels {
val, ok := labels[label]
if iCurry < len(oldCurry) && oldCurry[iCurry].index == i {
if ok {
return nil, fmt.Errorf("label name %q is already curried", label)
}
newCurry = append(newCurry, oldCurry[iCurry])
iCurry++
} else {
if !ok {
continue // Label stays uncurried.
}
newCurry = append(newCurry, curriedLabelValue{i, val})
}
}
if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 {
return nil, fmt.Errorf("%d unknown label(s) found during currying", l)
}
return &metricVec{
metricMap: m.metricMap,
curry: newCurry,
hashAdd: m.hashAdd,
hashAddByte: m.hashAddByte,
}, nil
}
func (m *metricVec) getMetricWithLabelValues(lvs ...string) (Metric, error) {
h, err := m.hashLabelValues(lvs)
if err != nil {
return nil, err
}
return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
}
func (m *metricVec) getMetricWith(labels Labels) (Metric, error) {
h, err := m.hashLabels(labels)
if err != nil {
return nil, err
}
return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil
}
func (m *metricVec) hashLabelValues(vals []string) (uint64, error) {
if err := validateLabelValues(vals, len(m.desc.variableLabels)-len(m.curry)); err != nil {
return 0, err
}
var (
h = hashNew()
curry = m.curry
iVals, iCurry int
)
for i := 0; i < len(m.desc.variableLabels); i++ {
if iCurry < len(curry) && curry[iCurry].index == i {
h = m.hashAdd(h, curry[iCurry].value)
iCurry++
} else {
h = m.hashAdd(h, vals[iVals])
iVals++
}
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
func (m *metricVec) hashLabels(labels Labels) (uint64, error) {
if err := validateValuesInLabels(labels, len(m.desc.variableLabels)-len(m.curry)); err != nil {
return 0, err
}
var (
h = hashNew()
curry = m.curry
iCurry int
)
for i, label := range m.desc.variableLabels {
val, ok := labels[label]
if iCurry < len(curry) && curry[iCurry].index == i {
if ok {
return 0, fmt.Errorf("label name %q is already curried", label)
}
h = m.hashAdd(h, curry[iCurry].value)
iCurry++
} else {
if !ok {
return 0, fmt.Errorf("label name %q missing in label map", label)
}
h = m.hashAdd(h, val)
}
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
// metricWithLabelValues provides the metric and its label values for
// disambiguation on hash collision.
type metricWithLabelValues struct {
values []string
metric Metric
}
// curriedLabelValue sets the curried value for a label at the given index.
type curriedLabelValue struct {
index int
value string
}
// metricMap is a helper for metricVec and shared between differently curried
// metricVecs.
type metricMap struct {
mtx sync.RWMutex // Protects metrics.
metrics map[uint64][]metricWithLabelValues
desc *Desc
newMetric func(labelValues ...string) Metric
}
// Describe implements Collector. It will send exactly one Desc to the provided
// channel.
func (m *metricMap) Describe(ch chan<- *Desc) {
ch <- m.desc
}
// Collect implements Collector.
func (m *metricMap) Collect(ch chan<- Metric) {
m.mtx.RLock()
defer m.mtx.RUnlock()
for _, metrics := range m.metrics {
for _, metric := range metrics {
ch <- metric.metric
}
}
}
// Reset deletes all metrics in this vector.
func (m *metricMap) Reset() {
m.mtx.Lock()
defer m.mtx.Unlock()
for h := range m.metrics {
delete(m.metrics, h)
}
}
// deleteByHashWithLabelValues removes the metric from the hash bucket h. If
// there are multiple matches in the bucket, use lvs to select a metric and
// remove only that metric.
func (m *metricMap) deleteByHashWithLabelValues(
h uint64, lvs []string, curry []curriedLabelValue,
) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
metrics, ok := m.metrics[h]
if !ok {
return false
}
i := findMetricWithLabelValues(metrics, lvs, curry)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
} else {
delete(m.metrics, h)
}
return true
}
// deleteByHashWithLabels removes the metric from the hash bucket h. If there
// are multiple matches in the bucket, use lvs to select a metric and remove
// only that metric.
func (m *metricMap) deleteByHashWithLabels(
h uint64, labels Labels, curry []curriedLabelValue,
) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
metrics, ok := m.metrics[h]
if !ok {
return false
}
i := findMetricWithLabels(m.desc, metrics, labels, curry)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
} else {
delete(m.metrics, h)
}
return true
}
// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *metricMap) getOrCreateMetricWithLabelValues(
hash uint64, lvs []string, curry []curriedLabelValue,
) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs, curry)
m.mtx.RUnlock()
if ok {
return metric
}
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs, curry)
if !ok {
inlinedLVs := inlineLabelValues(lvs, curry)
metric = m.newMetric(inlinedLVs...)
m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: inlinedLVs, metric: metric})
}
return metric
}
// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *metricMap) getOrCreateMetricWithLabels(
hash uint64, labels Labels, curry []curriedLabelValue,
) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithHashAndLabels(hash, labels, curry)
m.mtx.RUnlock()
if ok {
return metric
}
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithHashAndLabels(hash, labels, curry)
if !ok {
lvs := extractLabelValues(m.desc, labels, curry)
metric = m.newMetric(lvs...)
m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: lvs, metric: metric})
}
return metric
}
// getMetricWithHashAndLabelValues gets a metric while handling possible
// collisions in the hash space. Must be called while holding the read mutex.
func (m *metricMap) getMetricWithHashAndLabelValues(
h uint64, lvs []string, curry []curriedLabelValue,
) (Metric, bool) {
metrics, ok := m.metrics[h]
if ok {
if i := findMetricWithLabelValues(metrics, lvs, curry); i < len(metrics) {
return metrics[i].metric, true
}
}
return nil, false
}
// getMetricWithHashAndLabels gets a metric while handling possible collisions in
// the hash space. Must be called while holding read mutex.
func (m *metricMap) getMetricWithHashAndLabels(
h uint64, labels Labels, curry []curriedLabelValue,
) (Metric, bool) {
metrics, ok := m.metrics[h]
if ok {
if i := findMetricWithLabels(m.desc, metrics, labels, curry); i < len(metrics) {
return metrics[i].metric, true
}
}
return nil, false
}
// findMetricWithLabelValues returns the index of the matching metric or
// len(metrics) if not found.
func findMetricWithLabelValues(
metrics []metricWithLabelValues, lvs []string, curry []curriedLabelValue,
) int {
for i, metric := range metrics {
if matchLabelValues(metric.values, lvs, curry) {
return i
}
}
return len(metrics)
}
// findMetricWithLabels returns the index of the matching metric or len(metrics)
// if not found.
func findMetricWithLabels(
desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
) int {
for i, metric := range metrics {
if matchLabels(desc, metric.values, labels, curry) {
return i
}
}
return len(metrics)
}
func matchLabelValues(values []string, lvs []string, curry []curriedLabelValue) bool {
if len(values) != len(lvs)+len(curry) {
return false
}
var iLVs, iCurry int
for i, v := range values {
if iCurry < len(curry) && curry[iCurry].index == i {
if v != curry[iCurry].value {
return false
}
iCurry++
continue
}
if v != lvs[iLVs] {
return false
}
iLVs++
}
return true
}
func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
if len(values) != len(labels)+len(curry) {
return false
}
iCurry := 0
for i, k := range desc.variableLabels {
if iCurry < len(curry) && curry[iCurry].index == i {
if values[i] != curry[iCurry].value {
return false
}
iCurry++
continue
}
if values[i] != labels[k] {
return false
}
}
return true
}
func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) []string {
labelValues := make([]string, len(labels)+len(curry))
iCurry := 0
for i, k := range desc.variableLabels {
if iCurry < len(curry) && curry[iCurry].index == i {
labelValues[i] = curry[iCurry].value
iCurry++
continue
}
labelValues[i] = labels[k]
}
return labelValues
}
func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string {
labelValues := make([]string, len(lvs)+len(curry))
var iCurry, iLVs int
for i := range labelValues {
if iCurry < len(curry) && curry[iCurry].index == i {
labelValues[i] = curry[iCurry].value
iCurry++
continue
}
labelValues[i] = lvs[iLVs]
iLVs++
}
return labelValues
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"testing"
dto "github.com/prometheus/client_model/go"
)
func TestDelete(t *testing.T) {
vec := NewGaugeVec(
GaugeOpts{
Name: "test",
Help: "helpless",
},
[]string{"l1", "l2"},
)
testDelete(t, vec)
}
func TestDeleteWithCollisions(t *testing.T) {
vec := NewGaugeVec(
GaugeOpts{
Name: "test",
Help: "helpless",
},
[]string{"l1", "l2"},
)
vec.hashAdd = func(h uint64, s string) uint64 { return 1 }
vec.hashAddByte = func(h uint64, b byte) uint64 { return 1 }
testDelete(t, vec)
}
func testDelete(t *testing.T, vec *GaugeVec) {
if got, want := vec.Delete(Labels{"l1": "v1", "l2": "v2"}), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
if got, want := vec.Delete(Labels{"l1": "v1", "l2": "v2"}), true; got != want {
t.Errorf("got %v, want %v", got, want)
}
if got, want := vec.Delete(Labels{"l1": "v1", "l2": "v2"}), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
if got, want := vec.Delete(Labels{"l2": "v2", "l1": "v1"}), true; got != want {
t.Errorf("got %v, want %v", got, want)
}
if got, want := vec.Delete(Labels{"l2": "v2", "l1": "v1"}), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
if got, want := vec.Delete(Labels{"l2": "v1", "l1": "v2"}), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
if got, want := vec.Delete(Labels{"l1": "v1"}), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
}
func TestDeleteLabelValues(t *testing.T) {
vec := NewGaugeVec(
GaugeOpts{
Name: "test",
Help: "helpless",
},
[]string{"l1", "l2"},
)
testDeleteLabelValues(t, vec)
}
func TestDeleteLabelValuesWithCollisions(t *testing.T) {
vec := NewGaugeVec(
GaugeOpts{
Name: "test",
Help: "helpless",
},
[]string{"l1", "l2"},
)
vec.hashAdd = func(h uint64, s string) uint64 { return 1 }
vec.hashAddByte = func(h uint64, b byte) uint64 { return 1 }
testDeleteLabelValues(t, vec)
}
func testDeleteLabelValues(t *testing.T, vec *GaugeVec) {
if got, want := vec.DeleteLabelValues("v1", "v2"), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
vec.With(Labels{"l1": "v1", "l2": "v3"}).(Gauge).Set(42) // Add junk data for collision.
if got, want := vec.DeleteLabelValues("v1", "v2"), true; got != want {
t.Errorf("got %v, want %v", got, want)
}
if got, want := vec.DeleteLabelValues("v1", "v2"), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
if got, want := vec.DeleteLabelValues("v1", "v3"), true; got != want {
t.Errorf("got %v, want %v", got, want)
}
vec.With(Labels{"l1": "v1", "l2": "v2"}).(Gauge).Set(42)
// Delete out of order.
if got, want := vec.DeleteLabelValues("v2", "v1"), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
if got, want := vec.DeleteLabelValues("v1"), false; got != want {
t.Errorf("got %v, want %v", got, want)
}
}
func TestMetricVec(t *testing.T) {
vec := NewGaugeVec(
GaugeOpts{
Name: "test",
Help: "helpless",
},
[]string{"l1", "l2"},
)
testMetricVec(t, vec)
}
func TestMetricVecWithCollisions(t *testing.T) {
vec := NewGaugeVec(
GaugeOpts{
Name: "test",
Help: "helpless",
},
[]string{"l1", "l2"},
)
vec.hashAdd = func(h uint64, s string) uint64 { return 1 }
vec.hashAddByte = func(h uint64, b byte) uint64 { return 1 }
testMetricVec(t, vec)
}
func testMetricVec(t *testing.T, vec *GaugeVec) {
vec.Reset() // Actually test Reset now!
var pair [2]string
// Keep track of metrics.
expected := map[[2]string]int{}
for i := 0; i < 1000; i++ {
pair[0], pair[1] = fmt.Sprint(i%4), fmt.Sprint(i%5) // Varying combinations multiples.
expected[pair]++
vec.WithLabelValues(pair[0], pair[1]).Inc()
expected[[2]string{"v1", "v2"}]++
vec.WithLabelValues("v1", "v2").(Gauge).Inc()
}
var total int
for _, metrics := range vec.metricMap.metrics {
for _, metric := range metrics {
total++
copy(pair[:], metric.values)
var metricOut dto.Metric
if err := metric.metric.Write(&metricOut); err != nil {
t.Fatal(err)
}
actual := *metricOut.Gauge.Value
var actualPair [2]string
for i, label := range metricOut.Label {
actualPair[i] = *label.Value
}
// Test output pair against metric.values to ensure we've selected
// the right one. We check this to ensure the below check means
// anything at all.
if actualPair != pair {
t.Fatalf("unexpected pair association in metric map: %v != %v", actualPair, pair)
}
if actual != float64(expected[pair]) {
t.Fatalf("incorrect counter value for %v: %v != %v", pair, actual, expected[pair])
}
}
}
if total != len(expected) {
t.Fatalf("unexpected number of metrics: %v != %v", total, len(expected))
}
vec.Reset()
if len(vec.metricMap.metrics) > 0 {
t.Fatalf("reset failed")
}
}
func TestCounterVecEndToEndWithCollision(t *testing.T) {
vec := NewCounterVec(
CounterOpts{
Name: "test",
Help: "helpless",
},
[]string{"labelname"},
)
vec.WithLabelValues("77kepQFQ8Kl").Inc()
vec.WithLabelValues("!0IC=VloaY").Add(2)
m := &dto.Metric{}
if err := vec.WithLabelValues("77kepQFQ8Kl").Write(m); err != nil {
t.Fatal(err)
}
if got, want := m.GetLabel()[0].GetValue(), "77kepQFQ8Kl"; got != want {
t.Errorf("got label value %q, want %q", got, want)
}
if got, want := m.GetCounter().GetValue(), 1.; got != want {
t.Errorf("got value %f, want %f", got, want)
}
m.Reset()
if err := vec.WithLabelValues("!0IC=VloaY").Write(m); err != nil {
t.Fatal(err)
}
if got, want := m.GetLabel()[0].GetValue(), "!0IC=VloaY"; got != want {
t.Errorf("got label value %q, want %q", got, want)
}
if got, want := m.GetCounter().GetValue(), 2.; got != want {
t.Errorf("got value %f, want %f", got, want)
}
}
func TestCurryVec(t *testing.T) {
vec := NewCounterVec(
CounterOpts{
Name: "test",
Help: "helpless",
},
[]string{"one", "two", "three"},
)
testCurryVec(t, vec)
}
func TestCurryVecWithCollisions(t *testing.T) {
vec := NewCounterVec(
CounterOpts{
Name: "test",
Help: "helpless",
},
[]string{"one", "two", "three"},
)
vec.hashAdd = func(h uint64, s string) uint64 { return 1 }
vec.hashAddByte = func(h uint64, b byte) uint64 { return 1 }
testCurryVec(t, vec)
}
func testCurryVec(t *testing.T, vec *CounterVec) {
assertMetrics := func(t *testing.T) {
n := 0
for _, m := range vec.metricMap.metrics {
n += len(m)
}
if n != 2 {
t.Error("expected two metrics, got", n)
}
m := &dto.Metric{}
c1, err := vec.GetMetricWithLabelValues("1", "2", "3")
if err != nil {
t.Fatal("unexpected error getting metric:", err)
}
c1.Write(m)
if want, got := 1., m.GetCounter().GetValue(); want != got {
t.Errorf("want %f as counter value, got %f", want, got)
}
m.Reset()
c2, err := vec.GetMetricWithLabelValues("11", "22", "33")
if err != nil {
t.Fatal("unexpected error getting metric:", err)
}
c2.Write(m)
if want, got := 1., m.GetCounter().GetValue(); want != got {
t.Errorf("want %f as counter value, got %f", want, got)
}
}
assertNoMetric := func(t *testing.T) {
if n := len(vec.metricMap.metrics); n != 0 {
t.Error("expected no metrics, got", n)
}
}
t.Run("zero labels", func(t *testing.T) {
c1 := vec.MustCurryWith(nil)
c2 := vec.MustCurryWith(nil)
c1.WithLabelValues("1", "2", "3").Inc()
c2.With(Labels{"one": "11", "two": "22", "three": "33"}).Inc()
assertMetrics(t)
if !c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("11", "22", "33") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("first label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"one": "1"})
c2 := vec.MustCurryWith(Labels{"one": "11"})
c1.WithLabelValues("2", "3").Inc()
c2.With(Labels{"two": "22", "three": "33"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22", "three": "33"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("2", "3") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2", "three": "3"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("22", "33") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("middle label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"two": "2"})
c2 := vec.MustCurryWith(Labels{"two": "22"})
c1.WithLabelValues("1", "3").Inc()
c2.With(Labels{"one": "11", "three": "33"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"one": "11", "three": "33"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("1", "3") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"one": "1", "three": "3"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("11", "33") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("last label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3"})
c2 := vec.MustCurryWith(Labels{"three": "33"})
c1.WithLabelValues("1", "2").Inc()
c2.With(Labels{"one": "11", "two": "22"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22", "one": "11"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("1", "2") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2", "one": "1"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("11", "22") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("two labels", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3", "one": "1"})
c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11"})
c1.WithLabelValues("2").Inc()
c2.With(Labels{"two": "22"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("2") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("22") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("all labels", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3", "two": "2", "one": "1"})
c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11", "two": "22"})
c1.WithLabelValues().Inc()
c2.With(nil).Inc()
assertMetrics(t)
if !c1.Delete(Labels{}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues() {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("double curry", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3"}).MustCurryWith(Labels{"one": "1"})
c2 := vec.MustCurryWith(Labels{"three": "33"}).MustCurryWith(Labels{"one": "11"})
c1.WithLabelValues("2").Inc()
c2.With(Labels{"two": "22"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("2") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("22") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("use already curried label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3"})
if _, err := c1.GetMetricWithLabelValues("1", "2", "3"); err == nil {
t.Error("expected error when using already curried label")
}
if _, err := c1.GetMetricWith(Labels{"one": "1", "two": "2", "three": "3"}); err == nil {
t.Error("expected error when using already curried label")
}
assertNoMetric(t)
c1.WithLabelValues("1", "2").Inc()
if c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"one": "1", "two": "2"}) {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("curry already curried label", func(t *testing.T) {
if _, err := vec.MustCurryWith(Labels{"three": "3"}).CurryWith(Labels{"three": "33"}); err == nil {
t.Error("currying unexpectedly succeeded")
} else if err.Error() != `label name "three" is already curried` {
t.Error("currying returned unexpected error:", err)
}
})
t.Run("unknown label", func(t *testing.T) {
if _, err := vec.CurryWith(Labels{"foo": "bar"}); err == nil {
t.Error("currying unexpectedly succeeded")
} else if err.Error() != "1 unknown label(s) found during currying" {
t.Error("currying returned unexpected error:", err)
}
})
}
func BenchmarkMetricVecWithLabelValuesBasic(b *testing.B) {
benchmarkMetricVecWithLabelValues(b, map[string][]string{
"l1": {"onevalue"},
"l2": {"twovalue"},
})
}
func BenchmarkMetricVecWithLabelValues2Keys10ValueCardinality(b *testing.B) {
benchmarkMetricVecWithLabelValuesCardinality(b, 2, 10)
}
func BenchmarkMetricVecWithLabelValues4Keys10ValueCardinality(b *testing.B) {
benchmarkMetricVecWithLabelValuesCardinality(b, 4, 10)
}
func BenchmarkMetricVecWithLabelValues2Keys100ValueCardinality(b *testing.B) {
benchmarkMetricVecWithLabelValuesCardinality(b, 2, 100)
}
func BenchmarkMetricVecWithLabelValues10Keys100ValueCardinality(b *testing.B) {
benchmarkMetricVecWithLabelValuesCardinality(b, 10, 100)
}
func BenchmarkMetricVecWithLabelValues10Keys1000ValueCardinality(b *testing.B) {
benchmarkMetricVecWithLabelValuesCardinality(b, 10, 1000)
}
func benchmarkMetricVecWithLabelValuesCardinality(b *testing.B, nkeys, nvalues int) {
labels := map[string][]string{}
for i := 0; i < nkeys; i++ {
var (
k = fmt.Sprintf("key-%v", i)
vs = make([]string, 0, nvalues)
)
for j := 0; j < nvalues; j++ {
vs = append(vs, fmt.Sprintf("value-%v", j))
}
labels[k] = vs
}
benchmarkMetricVecWithLabelValues(b, labels)
}
func benchmarkMetricVecWithLabelValues(b *testing.B, labels map[string][]string) {
var keys []string
for k := range labels { // Map order dependent, who cares though.
keys = append(keys, k)
}
values := make([]string, len(labels)) // Value cache for permutations.
vec := NewGaugeVec(
GaugeOpts{
Name: "test",
Help: "helpless",
},
keys,
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
// Varies input across provide map entries based on key size.
for j, k := range keys {
candidates := labels[k]
values[j] = candidates[i%len(candidates)]
}
vec.WithLabelValues(values...)
}
}

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@ -0,0 +1,109 @@
## 0.8.0 / 2016-08-17
* [CHANGE] Registry is doing more consistency checks. This might break
existing setups that used to export inconsistent metrics.
* [CHANGE] Pushing to Pushgateway moved to package `push` and changed to allow
arbitrary grouping.
* [CHANGE] Removed `SelfCollector`.
* [CHANGE] Removed `PanicOnCollectError` and `EnableCollectChecks` methods.
* [CHANGE] Moved packages to the prometheus/common repo: `text`, `model`,
`extraction`.
* [CHANGE] Deprecated a number of functions.
* [FEATURE] Allow custom registries. Added `Registerer` and `Gatherer`
interfaces.
* [FEATURE] Separated HTTP exposition, allowing custom HTTP handlers (package
`promhttp`) and enabling the creation of other exposition mechanisms.
* [FEATURE] `MustRegister` is variadic now, allowing registration of many
collectors in one call.
* [FEATURE] Added HTTP API v1 package.
* [ENHANCEMENT] Numerous documentation improvements.
* [ENHANCEMENT] Improved metric sorting.
* [ENHANCEMENT] Inlined fnv64a hashing for improved performance.
* [ENHANCEMENT] Several test improvements.
* [BUGFIX] Handle collisions in MetricVec.
## 0.7.0 / 2015-07-27
* [CHANGE] Rename ExporterLabelPrefix to ExportedLabelPrefix.
* [BUGFIX] Closed gaps in metric consistency check.
* [BUGFIX] Validate LabelName/LabelSet on JSON unmarshaling.
* [ENHANCEMENT] Document the possibility to create "empty" metrics in
a metric vector.
* [ENHANCEMENT] Fix and clarify various doc comments and the README.md.
* [ENHANCEMENT] (Kind of) solve "The Proxy Problem" of http.InstrumentHandler.
* [ENHANCEMENT] Change responseWriterDelegator.written to int64.
## 0.6.0 / 2015-06-01
* [CHANGE] Rename process_goroutines to go_goroutines.
* [ENHANCEMENT] Validate label names during YAML decoding.
* [ENHANCEMENT] Add LabelName regular expression.
* [BUGFIX] Ensure alignment of struct members for 32-bit systems.
## 0.5.0 / 2015-05-06
* [BUGFIX] Removed a weakness in the fingerprinting aka signature code.
This makes fingerprinting slower and more allocation-heavy, but the
weakness was too severe to be tolerated.
* [CHANGE] As a result of the above, Metric.Fingerprint is now returning
a different fingerprint. To keep the same fingerprint, the new method
Metric.FastFingerprint was introduced, which will be used by the
Prometheus server for storage purposes (implying that a collision
detection has to be added, too).
* [ENHANCEMENT] The Metric.Equal and Metric.Before do not depend on
fingerprinting anymore, removing the possibility of an undetected
fingerprint collision.
* [FEATURE] The Go collector in the exposition library includes garbage
collection stats.
* [FEATURE] The exposition library allows to create constant "throw-away"
summaries and histograms.
* [CHANGE] A number of new reserved labels and prefixes.
## 0.4.0 / 2015-04-08
* [CHANGE] Return NaN when Summaries have no observations yet.
* [BUGFIX] Properly handle Summary decay upon Write().
* [BUGFIX] Fix the documentation link to the consumption library.
* [FEATURE] Allow the metric family injection hook to merge with existing
metric families.
* [ENHANCEMENT] Removed cgo dependency and conditional compilation of procfs.
* [MAINTENANCE] Adjusted to changes in matttproud/golang_protobuf_extensions.
## 0.3.2 / 2015-03-11
* [BUGFIX] Fixed the receiver type of COWMetric.Set(). This method is
only used by the Prometheus server internally.
* [CLEANUP] Added licenses of vendored code left out by godep.
## 0.3.1 / 2015-03-04
* [ENHANCEMENT] Switched fingerprinting functions from own free list to
sync.Pool.
* [CHANGE] Makefile uses Go 1.4.2 now (only relevant for examples and tests).
## 0.3.0 / 2015-03-03
* [CHANGE] Changed the fingerprinting for metrics. THIS WILL INVALIDATE ALL
PERSISTED FINGERPRINTS. IF YOU COMPILE THE PROMETHEUS SERVER WITH THIS
VERSION, YOU HAVE TO WIPE THE PREVIOUSLY CREATED STORAGE.
* [CHANGE] LabelValuesToSignature removed. (Nobody had used it, and it was
arguably broken.)
* [CHANGE] Vendored dependencies. Those are only used by the Makefile. If
client_golang is used as a library, the vendoring will stay out of your way.
* [BUGFIX] Remove a weakness in the fingerprinting for metrics. (This made
the fingerprinting change above necessary.)
* [FEATURE] Added new fingerprinting functions SignatureForLabels and
SignatureWithoutLabels to be used by the Prometheus server. These functions
require fewer allocations than the ones currently used by the server.
## 0.2.0 / 2015-02-23
* [FEATURE] Introduce new Histagram metric type.
* [CHANGE] Ignore process collector errors for now (better error handling
pending).
* [CHANGE] Use clear error interface for process pidFn.
* [BUGFIX] Fix Go download links for several archs and OSes.
* [ENHANCEMENT] Massively improve Gauge and Counter performance.
* [ENHANCEMENT] Catch illegal label names for summaries in histograms.
* [ENHANCEMENT] Reduce allocations during fingerprinting.
* [ENHANCEMENT] Remove cgo dependency. procfs package will only be included if
both cgo is available and the build is for an OS with procfs.
* [CLEANUP] Clean up code style issues.
* [CLEANUP] Mark slow test as such and exclude them from travis.
* [CLEANUP] Update protobuf library package name.
* [CLEANUP] Updated vendoring of beorn7/perks.
## 0.1.0 / 2015-02-02
* [CLEANUP] Introduced semantic versioning and changelog. From now on,
changes will be reported in this file.

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# Contributing
Prometheus uses GitHub to manage reviews of pull requests.
* If you have a trivial fix or improvement, go ahead and create a pull request,
addressing (with `@...`) the maintainer of this repository (see
[MAINTAINERS.md](MAINTAINERS.md)) in the description of the pull request.
* If you plan to do something more involved, first discuss your ideas
on our [mailing list](https://groups.google.com/forum/?fromgroups#!forum/prometheus-developers).
This will avoid unnecessary work and surely give you and us a good deal
of inspiration.
* Relevant coding style guidelines are the [Go Code Review
Comments](https://code.google.com/p/go-wiki/wiki/CodeReviewComments)
and the _Formatting and style_ section of Peter Bourgon's [Go: Best
Practices for Production
Environments](http://peter.bourgon.org/go-in-production/#formatting-and-style).

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<!--
If you are unhappy how your favorite Go dependency management tool deals
with this repository, please do not file an issue but read
https://github.com/prometheus/client_golang#important-note-about-releases-versioning-tagging-stability-and-your-favorite-go-dependency-management-tool
instead. Thank you very much.
-->

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for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
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7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
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of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
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8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
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Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
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Copyright [yyyy] [name of copyright owner]
Licensed under the Apache License, Version 2.0 (the "License");
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Unless required by applicable law or agreed to in writing, software
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limitations under the License.

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* Björn Rabenstein <beorn@soundcloud.com>

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Prometheus instrumentation library for Go applications
Copyright 2012-2015 The Prometheus Authors
This product includes software developed at
SoundCloud Ltd. (http://soundcloud.com/).
The following components are included in this product:
perks - a fork of https://github.com/bmizerany/perks
https://github.com/beorn7/perks
Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
See https://github.com/beorn7/perks/blob/master/README.md for license details.
Go support for Protocol Buffers - Google's data interchange format
http://github.com/golang/protobuf/
Copyright 2010 The Go Authors
See source code for license details.
Support for streaming Protocol Buffer messages for the Go language (golang).
https://github.com/matttproud/golang_protobuf_extensions
Copyright 2013 Matt T. Proud
Licensed under the Apache License, Version 2.0

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# Prometheus Go client library
[![Build Status](https://travis-ci.org/prometheus/client_golang.svg?branch=master)](https://travis-ci.org/prometheus/client_golang)
[![Go Report Card](https://goreportcard.com/badge/github.com/prometheus/client_golang)](https://goreportcard.com/report/github.com/prometheus/client_golang)
[![go-doc](https://godoc.org/github.com/prometheus/client_golang?status.svg)](https://godoc.org/github.com/prometheus/client_golang)
This is the [Go](http://golang.org) client library for
[Prometheus](http://prometheus.io). It has two separate parts, one for
instrumenting application code, and one for creating clients that talk to the
Prometheus HTTP API.
__This library requires Go1.7 or later.__
## Important note about releases, versioning, tagging, stability, and your favorite Go dependency management tool
While our goal is to follow [Semantic Versioning](https://semver.org/), this
repository is still pre-1.0.0. To quote the
[Semantic Versioning spec](https://semver.org/#spec-item-4): “Anything may
change at any time. The public API should not be considered stable.” We know
that this is at odds with the widespread use of this library. However, just
declaring something 1.0.0 doesn't make it 1.0.0. Instead, we are working
towards a 1.0.0 release that actually deserves its major version number.
Having said that, we aim for always keeping the tip of master in a workable
state and for only introducing ”mildly” breaking changes up to and including
[v0.9.0](https://github.com/prometheus/client_golang/milestone/1). After that,
a number of ”hard” breaking changes are planned, see the
[v0.10.0 milestone](https://github.com/prometheus/client_golang/milestone/2),
which should get the library much closer to 1.0.0 state.
Dependency management in Go projects is still in flux, and there are many tools
floating around. While [dep](https://golang.github.io/dep/) might develop into
the de-facto standard tool, it is still officially experimental. The roadmap
for this library has been laid out with a lot of sometimes painful experience
in mind. We really cannot adjust it every other month to the needs of the
currently most popular or most promising Go dependency management tool. The
recommended course of action with dependency management tools is the following:
- Do not expect strict post-1.0.0 semver semantics prior to the 1.0.0
release. If your dependency management tool expects strict post-1.0.0 semver
semantics, you have to wait. Sorry.
- If you want absolute certainty, please lock to a specific commit. You can
also lock to tags, but please don't ask for more tagging. This would suggest
some release or stability testing procedure that simply is not in place. As
said above, we are aiming for stability of the tip of master, but if we
tagged every single commit, locking to tags would be the same as locking to
commits.
- If you want to get the newer features and improvements and are willing to
take the minor risk of newly introduced bugs and “mild” breakage, just always
update to the tip of master (which is essentially the original idea of Go
dependency management). We recommend to not use features marked as
_deprecated_ in this case.
- Once [v0.9.0](https://github.com/prometheus/client_golang/milestone/1) is
out, you could lock to v0.9.x to get bugfixes (and perhaps minor new
features) while avoiding the “hard” breakage that will come with post-0.9
features.
## Instrumenting applications
[![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/prometheus)](http://gocover.io/github.com/prometheus/client_golang/prometheus) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus)
The
[`prometheus` directory](https://github.com/prometheus/client_golang/tree/master/prometheus)
contains the instrumentation library. See the
[best practices section](http://prometheus.io/docs/practices/naming/) of the
Prometheus documentation to learn more about instrumenting applications.
The
[`examples` directory](https://github.com/prometheus/client_golang/tree/master/examples)
contains simple examples of instrumented code.
## Client for the Prometheus HTTP API
[![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/api/prometheus/v1)](http://gocover.io/github.com/prometheus/client_golang/api/prometheus/v1) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/api/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/api)
The
[`api/prometheus` directory](https://github.com/prometheus/client_golang/tree/master/api/prometheus)
contains the client for the
[Prometheus HTTP API](http://prometheus.io/docs/querying/api/). It allows you
to write Go applications that query time series data from a Prometheus
server. It is still in alpha stage.
## Where is `model`, `extraction`, and `text`?
The `model` packages has been moved to
[`prometheus/common/model`](https://github.com/prometheus/common/tree/master/model).
The `extraction` and `text` packages are now contained in
[`prometheus/common/expfmt`](https://github.com/prometheus/common/tree/master/expfmt).
## Contributing and community
See the [contributing guidelines](CONTRIBUTING.md) and the
[Community section](http://prometheus.io/community/) of the homepage.

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0.8.0

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
// Package api provides clients for the HTTP APIs.
package api
import (
"context"
"io/ioutil"
"net"
"net/http"
"net/url"
"path"
"strings"
"time"
)
// DefaultRoundTripper is used if no RoundTripper is set in Config.
var DefaultRoundTripper http.RoundTripper = &http.Transport{
Proxy: http.ProxyFromEnvironment,
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
TLSHandshakeTimeout: 10 * time.Second,
}
// Config defines configuration parameters for a new client.
type Config struct {
// The address of the Prometheus to connect to.
Address string
// RoundTripper is used by the Client to drive HTTP requests. If not
// provided, DefaultRoundTripper will be used.
RoundTripper http.RoundTripper
}
func (cfg *Config) roundTripper() http.RoundTripper {
if cfg.RoundTripper == nil {
return DefaultRoundTripper
}
return cfg.RoundTripper
}
// Client is the interface for an API client.
type Client interface {
URL(ep string, args map[string]string) *url.URL
Do(context.Context, *http.Request) (*http.Response, []byte, error)
}
// NewClient returns a new Client.
//
// It is safe to use the returned Client from multiple goroutines.
func NewClient(cfg Config) (Client, error) {
u, err := url.Parse(cfg.Address)
if err != nil {
return nil, err
}
u.Path = strings.TrimRight(u.Path, "/")
return &httpClient{
endpoint: u,
client: http.Client{Transport: cfg.roundTripper()},
}, nil
}
type httpClient struct {
endpoint *url.URL
client http.Client
}
func (c *httpClient) URL(ep string, args map[string]string) *url.URL {
p := path.Join(c.endpoint.Path, ep)
for arg, val := range args {
arg = ":" + arg
p = strings.Replace(p, arg, val, -1)
}
u := *c.endpoint
u.Path = p
return &u
}
func (c *httpClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
if ctx != nil {
req = req.WithContext(ctx)
}
resp, err := c.client.Do(req)
defer func() {
if resp != nil {
resp.Body.Close()
}
}()
if err != nil {
return nil, nil, err
}
var body []byte
done := make(chan struct{})
go func() {
body, err = ioutil.ReadAll(resp.Body)
close(done)
}()
select {
case <-ctx.Done():
err = resp.Body.Close()
<-done
if err == nil {
err = ctx.Err()
}
case <-done:
}
return resp, body, err
}

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
package api
import (
"net/http"
"net/url"
"testing"
)
func TestConfig(t *testing.T) {
c := Config{}
if c.roundTripper() != DefaultRoundTripper {
t.Fatalf("expected default roundtripper for nil RoundTripper field")
}
}
func TestClientURL(t *testing.T) {
tests := []struct {
address string
endpoint string
args map[string]string
expected string
}{
{
address: "http://localhost:9090",
endpoint: "/test",
expected: "http://localhost:9090/test",
},
{
address: "http://localhost",
endpoint: "/test",
expected: "http://localhost/test",
},
{
address: "http://localhost:9090",
endpoint: "test",
expected: "http://localhost:9090/test",
},
{
address: "http://localhost:9090/prefix",
endpoint: "/test",
expected: "http://localhost:9090/prefix/test",
},
{
address: "https://localhost:9090/",
endpoint: "/test/",
expected: "https://localhost:9090/test",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param",
args: map[string]string{
"param": "content",
},
expected: "http://localhost:9090/test/content",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param/more/:param",
args: map[string]string{
"param": "content",
},
expected: "http://localhost:9090/test/content/more/content",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param/more/:foo",
args: map[string]string{
"param": "content",
"foo": "bar",
},
expected: "http://localhost:9090/test/content/more/bar",
},
{
address: "http://localhost:9090",
endpoint: "/test/:param",
args: map[string]string{
"nonexistent": "content",
},
expected: "http://localhost:9090/test/:param",
},
}
for _, test := range tests {
ep, err := url.Parse(test.address)
if err != nil {
t.Fatal(err)
}
hclient := &httpClient{
endpoint: ep,
client: http.Client{Transport: DefaultRoundTripper},
}
u := hclient.URL(test.endpoint, test.args)
if u.String() != test.expected {
t.Errorf("unexpected result: got %s, want %s", u, test.expected)
continue
}
}
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
// Package v1 provides bindings to the Prometheus HTTP API v1:
// http://prometheus.io/docs/querying/api/
package v1
import (
"context"
"encoding/json"
"fmt"
"net/http"
"strconv"
"time"
"github.com/prometheus/client_golang/api"
"github.com/prometheus/common/model"
)
const (
statusAPIError = 422
apiPrefix = "/api/v1"
epAlertManagers = apiPrefix + "/alertmanagers"
epQuery = apiPrefix + "/query"
epQueryRange = apiPrefix + "/query_range"
epLabelValues = apiPrefix + "/label/:name/values"
epSeries = apiPrefix + "/series"
epTargets = apiPrefix + "/targets"
epSnapshot = apiPrefix + "/admin/tsdb/snapshot"
epDeleteSeries = apiPrefix + "/admin/tsdb/delete_series"
epCleanTombstones = apiPrefix + "/admin/tsdb/clean_tombstones"
epConfig = apiPrefix + "/status/config"
epFlags = apiPrefix + "/status/flags"
)
// ErrorType models the different API error types.
type ErrorType string
// HealthStatus models the health status of a scrape target.
type HealthStatus string
const (
// Possible values for ErrorType.
ErrBadData ErrorType = "bad_data"
ErrTimeout = "timeout"
ErrCanceled = "canceled"
ErrExec = "execution"
ErrBadResponse = "bad_response"
// Possible values for HealthStatus.
HealthGood HealthStatus = "up"
HealthUnknown HealthStatus = "unknown"
HealthBad HealthStatus = "down"
)
// Error is an error returned by the API.
type Error struct {
Type ErrorType
Msg string
}
func (e *Error) Error() string {
return fmt.Sprintf("%s: %s", e.Type, e.Msg)
}
// Range represents a sliced time range.
type Range struct {
// The boundaries of the time range.
Start, End time.Time
// The maximum time between two slices within the boundaries.
Step time.Duration
}
// API provides bindings for Prometheus's v1 API.
type API interface {
// AlertManagers returns an overview of the current state of the Prometheus alert manager discovery.
AlertManagers(ctx context.Context) (AlertManagersResult, error)
// CleanTombstones removes the deleted data from disk and cleans up the existing tombstones.
CleanTombstones(ctx context.Context) error
// Config returns the current Prometheus configuration.
Config(ctx context.Context) (ConfigResult, error)
// DeleteSeries deletes data for a selection of series in a time range.
DeleteSeries(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) error
// Flags returns the flag values that Prometheus was launched with.
Flags(ctx context.Context) (FlagsResult, error)
// LabelValues performs a query for the values of the given label.
LabelValues(ctx context.Context, label string) (model.LabelValues, error)
// Query performs a query for the given time.
Query(ctx context.Context, query string, ts time.Time) (model.Value, error)
// QueryRange performs a query for the given range.
QueryRange(ctx context.Context, query string, r Range) (model.Value, error)
// Series finds series by label matchers.
Series(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) ([]model.LabelSet, error)
// Snapshot creates a snapshot of all current data into snapshots/<datetime>-<rand>
// under the TSDB's data directory and returns the directory as response.
Snapshot(ctx context.Context, skipHead bool) (SnapshotResult, error)
// Targets returns an overview of the current state of the Prometheus target discovery.
Targets(ctx context.Context) (TargetsResult, error)
}
// AlertManagersResult contains the result from querying the alertmanagers endpoint.
type AlertManagersResult struct {
Active []AlertManager `json:"activeAlertManagers"`
Dropped []AlertManager `json:"droppedAlertManagers"`
}
// AlertManager models a configured Alert Manager.
type AlertManager struct {
URL string `json:"url"`
}
// ConfigResult contains the result from querying the config endpoint.
type ConfigResult struct {
YAML string `json:"yaml"`
}
// FlagsResult contains the result from querying the flag endpoint.
type FlagsResult map[string]string
// SnapshotResult contains the result from querying the snapshot endpoint.
type SnapshotResult struct {
Name string `json:"name"`
}
// TargetsResult contains the result from querying the targets endpoint.
type TargetsResult struct {
Active []ActiveTarget `json:"activeTargets"`
Dropped []DroppedTarget `json:"droppedTargets"`
}
// ActiveTarget models an active Prometheus scrape target.
type ActiveTarget struct {
DiscoveredLabels model.LabelSet `json:"discoveredLabels"`
Labels model.LabelSet `json:"labels"`
ScrapeURL string `json:"scrapeUrl"`
LastError string `json:"lastError"`
LastScrape time.Time `json:"lastScrape"`
Health HealthStatus `json:"health"`
}
// DroppedTarget models a dropped Prometheus scrape target.
type DroppedTarget struct {
DiscoveredLabels model.LabelSet `json:"discoveredLabels"`
}
// queryResult contains result data for a query.
type queryResult struct {
Type model.ValueType `json:"resultType"`
Result interface{} `json:"result"`
// The decoded value.
v model.Value
}
func (qr *queryResult) UnmarshalJSON(b []byte) error {
v := struct {
Type model.ValueType `json:"resultType"`
Result json.RawMessage `json:"result"`
}{}
err := json.Unmarshal(b, &v)
if err != nil {
return err
}
switch v.Type {
case model.ValScalar:
var sv model.Scalar
err = json.Unmarshal(v.Result, &sv)
qr.v = &sv
case model.ValVector:
var vv model.Vector
err = json.Unmarshal(v.Result, &vv)
qr.v = vv
case model.ValMatrix:
var mv model.Matrix
err = json.Unmarshal(v.Result, &mv)
qr.v = mv
default:
err = fmt.Errorf("unexpected value type %q", v.Type)
}
return err
}
// NewAPI returns a new API for the client.
//
// It is safe to use the returned API from multiple goroutines.
func NewAPI(c api.Client) API {
return &httpAPI{client: apiClient{c}}
}
type httpAPI struct {
client api.Client
}
func (h *httpAPI) AlertManagers(ctx context.Context) (AlertManagersResult, error) {
u := h.client.URL(epAlertManagers, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return AlertManagersResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return AlertManagersResult{}, err
}
var res AlertManagersResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) CleanTombstones(ctx context.Context) error {
u := h.client.URL(epCleanTombstones, nil)
req, err := http.NewRequest(http.MethodPost, u.String(), nil)
if err != nil {
return err
}
_, _, err = h.client.Do(ctx, req)
return err
}
func (h *httpAPI) Config(ctx context.Context) (ConfigResult, error) {
u := h.client.URL(epConfig, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return ConfigResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return ConfigResult{}, err
}
var res ConfigResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) DeleteSeries(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) error {
u := h.client.URL(epDeleteSeries, nil)
q := u.Query()
for _, m := range matches {
q.Add("match[]", m)
}
q.Set("start", startTime.Format(time.RFC3339Nano))
q.Set("end", endTime.Format(time.RFC3339Nano))
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodPost, u.String(), nil)
if err != nil {
return err
}
_, _, err = h.client.Do(ctx, req)
return err
}
func (h *httpAPI) Flags(ctx context.Context) (FlagsResult, error) {
u := h.client.URL(epFlags, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return FlagsResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return FlagsResult{}, err
}
var res FlagsResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) LabelValues(ctx context.Context, label string) (model.LabelValues, error) {
u := h.client.URL(epLabelValues, map[string]string{"name": label})
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var labelValues model.LabelValues
err = json.Unmarshal(body, &labelValues)
return labelValues, err
}
func (h *httpAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, error) {
u := h.client.URL(epQuery, nil)
q := u.Query()
q.Set("query", query)
if !ts.IsZero() {
q.Set("time", ts.Format(time.RFC3339Nano))
}
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var qres queryResult
err = json.Unmarshal(body, &qres)
return model.Value(qres.v), err
}
func (h *httpAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, error) {
u := h.client.URL(epQueryRange, nil)
q := u.Query()
var (
start = r.Start.Format(time.RFC3339Nano)
end = r.End.Format(time.RFC3339Nano)
step = strconv.FormatFloat(r.Step.Seconds(), 'f', 3, 64)
)
q.Set("query", query)
q.Set("start", start)
q.Set("end", end)
q.Set("step", step)
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var qres queryResult
err = json.Unmarshal(body, &qres)
return model.Value(qres.v), err
}
func (h *httpAPI) Series(ctx context.Context, matches []string, startTime time.Time, endTime time.Time) ([]model.LabelSet, error) {
u := h.client.URL(epSeries, nil)
q := u.Query()
for _, m := range matches {
q.Add("match[]", m)
}
q.Set("start", startTime.Format(time.RFC3339Nano))
q.Set("end", endTime.Format(time.RFC3339Nano))
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return nil, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return nil, err
}
var mset []model.LabelSet
err = json.Unmarshal(body, &mset)
return mset, err
}
func (h *httpAPI) Snapshot(ctx context.Context, skipHead bool) (SnapshotResult, error) {
u := h.client.URL(epSnapshot, nil)
q := u.Query()
q.Set("skip_head", strconv.FormatBool(skipHead))
u.RawQuery = q.Encode()
req, err := http.NewRequest(http.MethodPost, u.String(), nil)
if err != nil {
return SnapshotResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return SnapshotResult{}, err
}
var res SnapshotResult
err = json.Unmarshal(body, &res)
return res, err
}
func (h *httpAPI) Targets(ctx context.Context) (TargetsResult, error) {
u := h.client.URL(epTargets, nil)
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
if err != nil {
return TargetsResult{}, err
}
_, body, err := h.client.Do(ctx, req)
if err != nil {
return TargetsResult{}, err
}
var res TargetsResult
err = json.Unmarshal(body, &res)
return res, err
}
// apiClient wraps a regular client and processes successful API responses.
// Successful also includes responses that errored at the API level.
type apiClient struct {
api.Client
}
type apiResponse struct {
Status string `json:"status"`
Data json.RawMessage `json:"data"`
ErrorType ErrorType `json:"errorType"`
Error string `json:"error"`
}
func (c apiClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
resp, body, err := c.Client.Do(ctx, req)
if err != nil {
return resp, body, err
}
code := resp.StatusCode
if code/100 != 2 && code != statusAPIError {
return resp, body, &Error{
Type: ErrBadResponse,
Msg: fmt.Sprintf("bad response code %d", resp.StatusCode),
}
}
var result apiResponse
if err = json.Unmarshal(body, &result); err != nil {
return resp, body, &Error{
Type: ErrBadResponse,
Msg: err.Error(),
}
}
if (code == statusAPIError) != (result.Status == "error") {
err = &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
}
}
if code == statusAPIError && result.Status == "error" {
err = &Error{
Type: result.ErrorType,
Msg: result.Error,
}
}
return resp, []byte(result.Data), err
}

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@ -0,0 +1,693 @@
// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build go1.7
package v1
import (
"context"
"encoding/json"
"fmt"
"net/http"
"net/url"
"reflect"
"strings"
"testing"
"time"
"github.com/prometheus/common/model"
)
type apiTest struct {
do func() (interface{}, error)
inErr error
inRes interface{}
reqPath string
reqParam url.Values
reqMethod string
res interface{}
err error
}
type apiTestClient struct {
*testing.T
curTest apiTest
}
func (c *apiTestClient) URL(ep string, args map[string]string) *url.URL {
path := ep
for k, v := range args {
path = strings.Replace(path, ":"+k, v, -1)
}
u := &url.URL{
Host: "test:9090",
Path: path,
}
return u
}
func (c *apiTestClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
test := c.curTest
if req.URL.Path != test.reqPath {
c.Errorf("unexpected request path: want %s, got %s", test.reqPath, req.URL.Path)
}
if req.Method != test.reqMethod {
c.Errorf("unexpected request method: want %s, got %s", test.reqMethod, req.Method)
}
b, err := json.Marshal(test.inRes)
if err != nil {
c.Fatal(err)
}
resp := &http.Response{}
if test.inErr != nil {
resp.StatusCode = statusAPIError
} else {
resp.StatusCode = http.StatusOK
}
return resp, b, test.inErr
}
func TestAPIs(t *testing.T) {
testTime := time.Now()
client := &apiTestClient{T: t}
promAPI := &httpAPI{
client: client,
}
doAlertManagers := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.AlertManagers(context.Background())
}
}
doCleanTombstones := func() func() (interface{}, error) {
return func() (interface{}, error) {
return nil, promAPI.CleanTombstones(context.Background())
}
}
doConfig := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Config(context.Background())
}
}
doDeleteSeries := func(matcher string, startTime time.Time, endTime time.Time) func() (interface{}, error) {
return func() (interface{}, error) {
return nil, promAPI.DeleteSeries(context.Background(), []string{matcher}, startTime, endTime)
}
}
doFlags := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Flags(context.Background())
}
}
doLabelValues := func(label string) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.LabelValues(context.Background(), label)
}
}
doQuery := func(q string, ts time.Time) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Query(context.Background(), q, ts)
}
}
doQueryRange := func(q string, rng Range) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.QueryRange(context.Background(), q, rng)
}
}
doSeries := func(matcher string, startTime time.Time, endTime time.Time) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Series(context.Background(), []string{matcher}, startTime, endTime)
}
}
doSnapshot := func(skipHead bool) func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Snapshot(context.Background(), skipHead)
}
}
doTargets := func() func() (interface{}, error) {
return func() (interface{}, error) {
return promAPI.Targets(context.Background())
}
}
queryTests := []apiTest{
{
do: doQuery("2", testTime),
inRes: &queryResult{
Type: model.ValScalar,
Result: &model.Scalar{
Value: 2,
Timestamp: model.TimeFromUnix(testTime.Unix()),
},
},
reqMethod: "GET",
reqPath: "/api/v1/query",
reqParam: url.Values{
"query": []string{"2"},
"time": []string{testTime.Format(time.RFC3339Nano)},
},
res: &model.Scalar{
Value: 2,
Timestamp: model.TimeFromUnix(testTime.Unix()),
},
},
{
do: doQuery("2", testTime),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/query",
reqParam: url.Values{
"query": []string{"2"},
"time": []string{testTime.Format(time.RFC3339Nano)},
},
err: fmt.Errorf("some error"),
},
{
do: doQueryRange("2", Range{
Start: testTime.Add(-time.Minute),
End: testTime,
Step: time.Minute,
}),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/query_range",
reqParam: url.Values{
"query": []string{"2"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
"step": []string{time.Minute.String()},
},
err: fmt.Errorf("some error"),
},
{
do: doLabelValues("mylabel"),
inRes: []string{"val1", "val2"},
reqMethod: "GET",
reqPath: "/api/v1/label/mylabel/values",
res: model.LabelValues{"val1", "val2"},
},
{
do: doLabelValues("mylabel"),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/label/mylabel/values",
err: fmt.Errorf("some error"),
},
{
do: doSeries("up", testTime.Add(-time.Minute), testTime),
inRes: []map[string]string{
{
"__name__": "up",
"job": "prometheus",
"instance": "localhost:9090"},
},
reqMethod: "GET",
reqPath: "/api/v1/series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
res: []model.LabelSet{
model.LabelSet{
"__name__": "up",
"job": "prometheus",
"instance": "localhost:9090",
},
},
},
{
do: doSeries("up", testTime.Add(-time.Minute), testTime),
inErr: fmt.Errorf("some error"),
reqMethod: "GET",
reqPath: "/api/v1/series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
err: fmt.Errorf("some error"),
},
{
do: doSnapshot(true),
inRes: map[string]string{
"name": "20171210T211224Z-2be650b6d019eb54",
},
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/snapshot",
reqParam: url.Values{
"skip_head": []string{"true"},
},
res: SnapshotResult{
Name: "20171210T211224Z-2be650b6d019eb54",
},
},
{
do: doSnapshot(true),
inErr: fmt.Errorf("some error"),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/snapshot",
err: fmt.Errorf("some error"),
},
{
do: doCleanTombstones(),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/clean_tombstones",
},
{
do: doCleanTombstones(),
inErr: fmt.Errorf("some error"),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/clean_tombstones",
err: fmt.Errorf("some error"),
},
{
do: doDeleteSeries("up", testTime.Add(-time.Minute), testTime),
inRes: []map[string]string{
{
"__name__": "up",
"job": "prometheus",
"instance": "localhost:9090"},
},
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/delete_series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
},
{
do: doDeleteSeries("up", testTime.Add(-time.Minute), testTime),
inErr: fmt.Errorf("some error"),
reqMethod: "POST",
reqPath: "/api/v1/admin/tsdb/delete_series",
reqParam: url.Values{
"match": []string{"up"},
"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
"end": []string{testTime.Format(time.RFC3339Nano)},
},
err: fmt.Errorf("some error"),
},
{
do: doConfig(),
reqMethod: "GET",
reqPath: "/api/v1/status/config",
inRes: map[string]string{
"yaml": "<content of the loaded config file in YAML>",
},
res: ConfigResult{
YAML: "<content of the loaded config file in YAML>",
},
},
{
do: doConfig(),
reqMethod: "GET",
reqPath: "/api/v1/status/config",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
{
do: doFlags(),
reqMethod: "GET",
reqPath: "/api/v1/status/flags",
inRes: map[string]string{
"alertmanager.notification-queue-capacity": "10000",
"alertmanager.timeout": "10s",
"log.level": "info",
"query.lookback-delta": "5m",
"query.max-concurrency": "20",
},
res: FlagsResult{
"alertmanager.notification-queue-capacity": "10000",
"alertmanager.timeout": "10s",
"log.level": "info",
"query.lookback-delta": "5m",
"query.max-concurrency": "20",
},
},
{
do: doFlags(),
reqMethod: "GET",
reqPath: "/api/v1/status/flags",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
{
do: doAlertManagers(),
reqMethod: "GET",
reqPath: "/api/v1/alertmanagers",
inRes: map[string]interface{}{
"activeAlertManagers": []map[string]string{
{
"url": "http://127.0.0.1:9091/api/v1/alerts",
},
},
"droppedAlertManagers": []map[string]string{
{
"url": "http://127.0.0.1:9092/api/v1/alerts",
},
},
},
res: AlertManagersResult{
Active: []AlertManager{
{
URL: "http://127.0.0.1:9091/api/v1/alerts",
},
},
Dropped: []AlertManager{
{
URL: "http://127.0.0.1:9092/api/v1/alerts",
},
},
},
},
{
do: doAlertManagers(),
reqMethod: "GET",
reqPath: "/api/v1/alertmanagers",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
{
do: doTargets(),
reqMethod: "GET",
reqPath: "/api/v1/targets",
inRes: map[string]interface{}{
"activeTargets": []map[string]interface{}{
{
"discoveredLabels": map[string]string{
"__address__": "127.0.0.1:9090",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "prometheus",
},
"labels": map[string]string{
"instance": "127.0.0.1:9090",
"job": "prometheus",
},
"scrapeUrl": "http://127.0.0.1:9090",
"lastError": "error while scraping target",
"lastScrape": testTime.UTC().Format(time.RFC3339Nano),
"health": "up",
},
},
"droppedTargets": []map[string]interface{}{
{
"discoveredLabels": map[string]string{
"__address__": "127.0.0.1:9100",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "node",
},
},
},
},
res: TargetsResult{
Active: []ActiveTarget{
{
DiscoveredLabels: model.LabelSet{
"__address__": "127.0.0.1:9090",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "prometheus",
},
Labels: model.LabelSet{
"instance": "127.0.0.1:9090",
"job": "prometheus",
},
ScrapeURL: "http://127.0.0.1:9090",
LastError: "error while scraping target",
LastScrape: testTime.UTC(),
Health: HealthGood,
},
},
Dropped: []DroppedTarget{
{
DiscoveredLabels: model.LabelSet{
"__address__": "127.0.0.1:9100",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "node",
},
},
},
},
},
{
do: doTargets(),
reqMethod: "GET",
reqPath: "/api/v1/targets",
inErr: fmt.Errorf("some error"),
err: fmt.Errorf("some error"),
},
}
var tests []apiTest
tests = append(tests, queryTests...)
for _, test := range tests {
client.curTest = test
res, err := test.do()
if test.err != nil {
if err == nil {
t.Errorf("expected error %q but got none", test.err)
continue
}
if err.Error() != test.err.Error() {
t.Errorf("unexpected error: want %s, got %s", test.err, err)
}
continue
}
if err != nil {
t.Errorf("unexpected error: %s", err)
continue
}
if !reflect.DeepEqual(res, test.res) {
t.Errorf("unexpected result: want %v, got %v", test.res, res)
}
}
}
type testClient struct {
*testing.T
ch chan apiClientTest
req *http.Request
}
type apiClientTest struct {
code int
response interface{}
expected string
err *Error
}
func (c *testClient) URL(ep string, args map[string]string) *url.URL {
return nil
}
func (c *testClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
if ctx == nil {
c.Fatalf("context was not passed down")
}
if req != c.req {
c.Fatalf("request was not passed down")
}
test := <-c.ch
var b []byte
var err error
switch v := test.response.(type) {
case string:
b = []byte(v)
default:
b, err = json.Marshal(v)
if err != nil {
c.Fatal(err)
}
}
resp := &http.Response{
StatusCode: test.code,
}
return resp, b, nil
}
func TestAPIClientDo(t *testing.T) {
tests := []apiClientTest{
{
response: &apiResponse{
Status: "error",
Data: json.RawMessage(`null`),
ErrorType: ErrBadData,
Error: "failed",
},
err: &Error{
Type: ErrBadData,
Msg: "failed",
},
code: statusAPIError,
expected: `null`,
},
{
response: &apiResponse{
Status: "error",
Data: json.RawMessage(`"test"`),
ErrorType: ErrTimeout,
Error: "timed out",
},
err: &Error{
Type: ErrTimeout,
Msg: "timed out",
},
code: statusAPIError,
expected: `test`,
},
{
response: "bad json",
err: &Error{
Type: ErrBadResponse,
Msg: "bad response code 400",
},
code: http.StatusBadRequest,
},
{
response: "bad json",
err: &Error{
Type: ErrBadResponse,
Msg: "invalid character 'b' looking for beginning of value",
},
code: statusAPIError,
},
{
response: &apiResponse{
Status: "success",
Data: json.RawMessage(`"test"`),
},
err: &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
},
code: statusAPIError,
},
{
response: &apiResponse{
Status: "success",
Data: json.RawMessage(`"test"`),
ErrorType: ErrTimeout,
Error: "timed out",
},
err: &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
},
code: statusAPIError,
},
{
response: &apiResponse{
Status: "error",
Data: json.RawMessage(`"test"`),
ErrorType: ErrTimeout,
Error: "timed out",
},
err: &Error{
Type: ErrBadResponse,
Msg: "inconsistent body for response code",
},
code: http.StatusOK,
},
}
tc := &testClient{
T: t,
ch: make(chan apiClientTest, 1),
req: &http.Request{},
}
client := &apiClient{tc}
for _, test := range tests {
tc.ch <- test
_, body, err := client.Do(context.Background(), tc.req)
if test.err != nil {
if err == nil {
t.Errorf("expected error %q but got none", test.err)
continue
}
if test.err.Error() != err.Error() {
t.Errorf("unexpected error: want %q, got %q", test.err, err)
}
continue
}
if err != nil {
t.Errorf("unexpeceted error %s", err)
continue
}
want, got := test.expected, string(body)
if want != got {
t.Errorf("unexpected body: want %q, got %q", want, got)
}
}
}

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# This Dockerfile builds an image for a client_golang example.
#
# Use as (from the root for the client_golang repository):
# docker build -f examples/$name/Dockerfile -t prometheus/golang-example-$name .
# Builder image, where we build the example.
FROM golang:1.9.0 AS builder
WORKDIR /go/src/github.com/prometheus/client_golang
COPY . .
WORKDIR /go/src/github.com/prometheus/client_golang/prometheus
RUN go get -d
WORKDIR /go/src/github.com/prometheus/client_golang/examples/random
RUN CGO_ENABLED=0 GOOS=linux go build -a -tags netgo -ldflags '-w'
# Final image.
FROM scratch
LABEL maintainer "The Prometheus Authors <prometheus-developers@googlegroups.com>"
COPY --from=builder /go/src/github.com/prometheus/client_golang/examples/random .
EXPOSE 8080
ENTRYPOINT ["/random"]

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// A simple example exposing fictional RPC latencies with different types of
// random distributions (uniform, normal, and exponential) as Prometheus
// metrics.
package main
import (
"flag"
"log"
"math"
"math/rand"
"net/http"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
var (
addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
uniformDomain = flag.Float64("uniform.domain", 0.0002, "The domain for the uniform distribution.")
normDomain = flag.Float64("normal.domain", 0.0002, "The domain for the normal distribution.")
normMean = flag.Float64("normal.mean", 0.00001, "The mean for the normal distribution.")
oscillationPeriod = flag.Duration("oscillation-period", 10*time.Minute, "The duration of the rate oscillation period.")
)
var (
// Create a summary to track fictional interservice RPC latencies for three
// distinct services with different latency distributions. These services are
// differentiated via a "service" label.
rpcDurations = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "rpc_durations_seconds",
Help: "RPC latency distributions.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"service"},
)
// The same as above, but now as a histogram, and only for the normal
// distribution. The buckets are targeted to the parameters of the
// normal distribution, with 20 buckets centered on the mean, each
// half-sigma wide.
rpcDurationsHistogram = prometheus.NewHistogram(prometheus.HistogramOpts{
Name: "rpc_durations_histogram_seconds",
Help: "RPC latency distributions.",
Buckets: prometheus.LinearBuckets(*normMean-5**normDomain, .5**normDomain, 20),
})
)
func init() {
// Register the summary and the histogram with Prometheus's default registry.
prometheus.MustRegister(rpcDurations)
prometheus.MustRegister(rpcDurationsHistogram)
}
func main() {
flag.Parse()
start := time.Now()
oscillationFactor := func() float64 {
return 2 + math.Sin(math.Sin(2*math.Pi*float64(time.Since(start))/float64(*oscillationPeriod)))
}
// Periodically record some sample latencies for the three services.
go func() {
for {
v := rand.Float64() * *uniformDomain
rpcDurations.WithLabelValues("uniform").Observe(v)
time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond)
}
}()
go func() {
for {
v := (rand.NormFloat64() * *normDomain) + *normMean
rpcDurations.WithLabelValues("normal").Observe(v)
rpcDurationsHistogram.Observe(v)
time.Sleep(time.Duration(75*oscillationFactor()) * time.Millisecond)
}
}()
go func() {
for {
v := rand.ExpFloat64() / 1e6
rpcDurations.WithLabelValues("exponential").Observe(v)
time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond)
}
}()
// Expose the registered metrics via HTTP.
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}

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# This Dockerfile builds an image for a client_golang example.
#
# Use as (from the root for the client_golang repository):
# docker build -f examples/$name/Dockerfile -t prometheus/golang-example-$name .
# Builder image, where we build the example.
FROM golang:1.9.0 AS builder
WORKDIR /go/src/github.com/prometheus/client_golang
COPY . .
WORKDIR /go/src/github.com/prometheus/client_golang/prometheus
RUN go get -d
WORKDIR /go/src/github.com/prometheus/client_golang/examples/simple
RUN CGO_ENABLED=0 GOOS=linux go build -a -tags netgo -ldflags '-w'
# Final image.
FROM scratch
LABEL maintainer "The Prometheus Authors <prometheus-developers@googlegroups.com>"
COPY --from=builder /go/src/github.com/prometheus/client_golang/examples/simple .
EXPOSE 8080
ENTRYPOINT ["/simple"]

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// A minimal example of how to include Prometheus instrumentation.
package main
import (
"flag"
"log"
"net/http"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
var addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
func main() {
flag.Parse()
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(*addr, nil))
}

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@ -0,0 +1 @@
See [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus).

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"sync"
"testing"
)
func BenchmarkCounterWithLabelValues(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Inc()
}
}
func BenchmarkCounterWithLabelValuesConcurrent(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
wg := sync.WaitGroup{}
for i := 0; i < 10; i++ {
wg.Add(1)
go func() {
for j := 0; j < b.N/10; j++ {
m.WithLabelValues("eins", "zwei", "drei").Inc()
}
wg.Done()
}()
}
wg.Wait()
}
func BenchmarkCounterWithMappedLabels(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.With(Labels{"two": "zwei", "one": "eins", "three": "drei"}).Inc()
}
}
func BenchmarkCounterWithPreparedMappedLabels(b *testing.B) {
m := NewCounterVec(
CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
labels := Labels{"two": "zwei", "one": "eins", "three": "drei"}
for i := 0; i < b.N; i++ {
m.With(labels).Inc()
}
}
func BenchmarkCounterNoLabels(b *testing.B) {
m := NewCounter(CounterOpts{
Name: "benchmark_counter",
Help: "A counter to benchmark it.",
})
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Inc()
}
}
func BenchmarkGaugeWithLabelValues(b *testing.B) {
m := NewGaugeVec(
GaugeOpts{
Name: "benchmark_gauge",
Help: "A gauge to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Set(3.1415)
}
}
func BenchmarkGaugeNoLabels(b *testing.B) {
m := NewGauge(GaugeOpts{
Name: "benchmark_gauge",
Help: "A gauge to benchmark it.",
})
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Set(3.1415)
}
}
func BenchmarkSummaryWithLabelValues(b *testing.B) {
m := NewSummaryVec(
SummaryOpts{
Name: "benchmark_summary",
Help: "A summary to benchmark it.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Observe(3.1415)
}
}
func BenchmarkSummaryNoLabels(b *testing.B) {
m := NewSummary(SummaryOpts{
Name: "benchmark_summary",
Help: "A summary to benchmark it.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Observe(3.1415)
}
}
func BenchmarkHistogramWithLabelValues(b *testing.B) {
m := NewHistogramVec(
HistogramOpts{
Name: "benchmark_histogram",
Help: "A histogram to benchmark it.",
},
[]string{"one", "two", "three"},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.WithLabelValues("eins", "zwei", "drei").Observe(3.1415)
}
}
func BenchmarkHistogramNoLabels(b *testing.B) {
m := NewHistogram(HistogramOpts{
Name: "benchmark_histogram",
Help: "A histogram to benchmark it.",
},
)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
m.Observe(3.1415)
}
}
func BenchmarkParallelCounter(b *testing.B) {
c := NewCounter(CounterOpts{
Name: "benchmark_counter",
Help: "A Counter to benchmark it.",
})
b.ReportAllocs()
b.ResetTimer()
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
c.Inc()
}
})
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Collector is the interface implemented by anything that can be used by
// Prometheus to collect metrics. A Collector has to be registered for
// collection. See Registerer.Register.
//
// The stock metrics provided by this package (Gauge, Counter, Summary,
// Histogram, Untyped) are also Collectors (which only ever collect one metric,
// namely itself). An implementer of Collector may, however, collect multiple
// metrics in a coordinated fashion and/or create metrics on the fly. Examples
// for collectors already implemented in this library are the metric vectors
// (i.e. collection of multiple instances of the same Metric but with different
// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
type Collector interface {
// Describe sends the super-set of all possible descriptors of metrics
// collected by this Collector to the provided channel and returns once
// the last descriptor has been sent. The sent descriptors fulfill the
// consistency and uniqueness requirements described in the Desc
// documentation. (It is valid if one and the same Collector sends
// duplicate descriptors. Those duplicates are simply ignored. However,
// two different Collectors must not send duplicate descriptors.) This
// method idempotently sends the same descriptors throughout the
// lifetime of the Collector. If a Collector encounters an error while
// executing this method, it must send an invalid descriptor (created
// with NewInvalidDesc) to signal the error to the registry.
Describe(chan<- *Desc)
// Collect is called by the Prometheus registry when collecting
// metrics. The implementation sends each collected metric via the
// provided channel and returns once the last metric has been sent. The
// descriptor of each sent metric is one of those returned by
// Describe. Returned metrics that share the same descriptor must differ
// in their variable label values. This method may be called
// concurrently and must therefore be implemented in a concurrency safe
// way. Blocking occurs at the expense of total performance of rendering
// all registered metrics. Ideally, Collector implementations support
// concurrent readers.
Collect(chan<- Metric)
}
// selfCollector implements Collector for a single Metric so that the Metric
// collects itself. Add it as an anonymous field to a struct that implements
// Metric, and call init with the Metric itself as an argument.
type selfCollector struct {
self Metric
}
// init provides the selfCollector with a reference to the metric it is supposed
// to collect. It is usually called within the factory function to create a
// metric. See example.
func (c *selfCollector) init(self Metric) {
c.self = self
}
// Describe implements Collector.
func (c *selfCollector) Describe(ch chan<- *Desc) {
ch <- c.self.Desc()
}
// Collect implements Collector.
func (c *selfCollector) Collect(ch chan<- Metric) {
ch <- c.self
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"math"
"sync/atomic"
dto "github.com/prometheus/client_model/go"
)
// Counter is a Metric that represents a single numerical value that only ever
// goes up. That implies that it cannot be used to count items whose number can
// also go down, e.g. the number of currently running goroutines. Those
// "counters" are represented by Gauges.
//
// A Counter is typically used to count requests served, tasks completed, errors
// occurred, etc.
//
// To create Counter instances, use NewCounter.
type Counter interface {
Metric
Collector
// Inc increments the counter by 1. Use Add to increment it by arbitrary
// non-negative values.
Inc()
// Add adds the given value to the counter. It panics if the value is <
// 0.
Add(float64)
}
// CounterOpts is an alias for Opts. See there for doc comments.
type CounterOpts Opts
// NewCounter creates a new Counter based on the provided CounterOpts.
//
// The returned implementation tracks the counter value in two separate
// variables, a float64 and a uint64. The latter is used to track calls of the
// Inc method and calls of the Add method with a value that can be represented
// as a uint64. This allows atomic increments of the counter with optimal
// performance. (It is common to have an Inc call in very hot execution paths.)
// Both internal tracking values are added up in the Write method. This has to
// be taken into account when it comes to precision and overflow behavior.
func NewCounter(opts CounterOpts) Counter {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
)
result := &counter{desc: desc, labelPairs: desc.constLabelPairs}
result.init(result) // Init self-collection.
return result
}
type counter struct {
// valBits contains the bits of the represented float64 value, while
// valInt stores values that are exact integers. Both have to go first
// in the struct to guarantee alignment for atomic operations.
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
valBits uint64
valInt uint64
selfCollector
desc *Desc
labelPairs []*dto.LabelPair
}
func (c *counter) Desc() *Desc {
return c.desc
}
func (c *counter) Add(v float64) {
if v < 0 {
panic(errors.New("counter cannot decrease in value"))
}
ival := uint64(v)
if float64(ival) == v {
atomic.AddUint64(&c.valInt, ival)
return
}
for {
oldBits := atomic.LoadUint64(&c.valBits)
newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
return
}
}
}
func (c *counter) Inc() {
atomic.AddUint64(&c.valInt, 1)
}
func (c *counter) Write(out *dto.Metric) error {
fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
ival := atomic.LoadUint64(&c.valInt)
val := fval + float64(ival)
return populateMetric(CounterValue, val, c.labelPairs, out)
}
// CounterVec is a Collector that bundles a set of Counters that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. number of HTTP requests, partitioned by response code and
// method). Create instances with NewCounterVec.
type CounterVec struct {
*metricVec
}
// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
// partitioned by the given label names.
func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &CounterVec{
metricVec: newMetricVec(desc, func(lvs ...string) Metric {
if len(lvs) != len(desc.variableLabels) {
panic(errInconsistentCardinality)
}
result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
result.init(result) // Init self-collection.
return result
}),
}
}
// GetMetricWithLabelValues returns the Counter for the given slice of label
// values (same order as the VariableLabels in Desc). If that combination of
// label values is accessed for the first time, a new Counter is created.
//
// It is possible to call this method without using the returned Counter to only
// create the new Counter but leave it at its starting value 0. See also the
// SummaryVec example.
//
// Keeping the Counter for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Counter from the CounterVec. In that case,
// the Counter will still exist, but it will not be exported anymore, even if a
// Counter with the same label values is created later.
//
// An error is returned if the number of label values is not the same as the
// number of VariableLabels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the GaugeVec example.
func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// GetMetricWith returns the Counter for the given Labels map (the label names
// must match those of the VariableLabels in Desc). If that label map is
// accessed for the first time, a new Counter is created. Implications of
// creating a Counter without using it and keeping the Counter for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
// myVec.WithLabelValues("404", "GET").Add(42)
func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
c, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return c
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
func (v *CounterVec) With(labels Labels) Counter {
c, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return c
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the CounterVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &CounterVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
// CounterFunc is a Counter whose value is determined at collect time by calling a
// provided function.
//
// To create CounterFunc instances, use NewCounterFunc.
type CounterFunc interface {
Metric
Collector
}
// NewCounterFunc creates a new CounterFunc based on the provided
// CounterOpts. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where a CounterFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe. The function should also honor
// the contract for a Counter (values only go up, not down), but compliance will
// not be checked.
func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), CounterValue, function)
}

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