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Add completely new push syntax 

This allows adding more options in elegant ways, showcased here by
HTTP basic auth and by injecting a custom http.Client.

Fixes #341 and #372.
This commit is contained in:
beorn7 2018-02-12 20:08:38 +01:00
parent a40133b69f
commit 3c2baee2d1
5 changed files with 415 additions and 126 deletions
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175
prometheus/push/deprecated.go Normal file
View File

@ -0,0 +1,175 @@
// 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.
// 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 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: It is recommended to use a Pusher created with New, which has a
// method HostnameGrouping.
func HostnameGroupingKey() map[string]string {
hostname, err := os.Hostname()
if err != nil {
return map[string]string{"instance": "unknown"}
}
return map[string]string{"instance": hostname}
}

26
prometheus/push/example_add_from_gatherer_test.go
View File

@ -53,10 +53,14 @@ func performBackup() (int, error) {
return 42, nil
}
func ExampleAddFromGatherer() {
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 at this time.
// Note that successTime is not registered.
pusher := push.New("http://pushgateway:9091", "db_backup").Gatherer(registry)
start := time.Now()
n, err := performBackup()
@ -67,18 +71,16 @@ func ExampleAddFromGatherer() {
if err != nil {
fmt.Println("DB backup failed:", err)
} else {
// Only now register successTime.
registry.MustRegister(successTime)
// 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()
}
// AddFromGatherer is used here rather than FromGatherer to not delete a
// previously pushed success timestamp in case of a failure of this
// backup.
if err := push.AddFromGatherer(
"db_backup", nil,
"http://pushgateway:9091",
registry,
); err != nil {
// 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)
}
}

11
prometheus/push/examples_test.go
View File

@ -20,17 +20,16 @@ import (
"github.com/prometheus/client_golang/prometheus/push"
)
func ExampleCollectors() {
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.Collectors(
"db_backup", push.HostnameGroupingKey(),
"http://pushgateway:9091",
completionTime,
); err != nil {
if err := push.New("http://pushgateway:9091", "db_backup").
Collector(completionTime).
HostnameGrouping().
Push(); err != nil {
fmt.Println("Could not push completion time to Pushgateway:", err)
}
}

265
prometheus/push/push.go
View File

@ -11,20 +11,28 @@
// See the License for the specific language governing permissions and
// limitations under the License.
// Copyright (c) 2013, The Prometheus Authors
// All rights reserved.
// 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:
//
// Use of this source code is governed by a BSD-style license that can be found
// in the LICENSE file.
// Package push provides functions to push metrics to a Pushgateway. The metrics
// to push are either collected from a provided registry, or from explicitly
// listed collectors.
// // Easy case:
// push.New("http://example.org/metrics", "my_job").Gatherer(myRegistry).Push()
//
// See the documentation of the Pushgateway to understand the meaning of the
// grouping parameters and the differences between push.Registry and
// push.Collectors on the one hand and push.AddRegistry and push.AddCollectors
// on the other hand: https://github.com/prometheus/pushgateway
// // Complex case:
// push.New("http://example.org/metrics", "my_job").
// Collector(myCollector1).
// Collector(myCollector2).
// HostnameGrouping().
// 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 (
@ -44,57 +52,164 @@ import (
const contentTypeHeader = "Content-Type"
// 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.
// 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 withe 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.
//
// 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.)
func FromGatherer(job string, grouping map[string]string, url string, g prometheus.Gatherer) error {
return push(job, grouping, url, g, "PUT")
// 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
}
// 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.)
func AddFromGatherer(job string, grouping map[string]string, url string, g prometheus.Gatherer) error {
return push(job, grouping, url, g, "POST")
if strings.HasSuffix(url, "/") {
url = url[:len(url)-1]
}
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)
err = 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)
return &Pusher{
error: err,
url: url,
job: job,
grouping: map[string]string{},
gatherers: prometheus.Gatherers{reg},
registerer: reg,
client: &http.Client{},
}
if strings.Contains(lv, "/") {
return fmt.Errorf("value of grouping label %s contains '/': %s", ln, lv)
}
// 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
}
// HostnameGrouping adds a label pair with “instance” as the name and the
// current hostname as the value to the grouping key of the Pusher. If the
// hostname cannot be determined, “unknown” is used as the label value. For
// further implications of setting a grouping key, see the Grouping method.
//
// For convenience, this method returns a pointer to the Pusher itself.
func (p *Pusher) HostnameGrouping() *Pusher {
hostname, err := os.Hostname()
if err != nil {
hostname = "unknown"
}
p.grouping["instance"] = hostname
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", pushURL, strings.Join(urlComponents, "/"))
pushURL := fmt.Sprintf("%s/metrics/job/%s", p.url, strings.Join(urlComponents, "/"))
mfs, err := g.Gather()
mfs, err := p.gatherers.Gather()
if err != nil {
return err
}
@ -107,7 +222,7 @@ func push(job string, grouping map[string]string, pushURL string, g prometheus.G
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 {
if _, ok := p.grouping[l.GetName()]; ok {
return fmt.Errorf(
"pushed metric %s (%s) already contains grouping label %s",
mf.GetName(), m, l.GetName(),
@ -121,8 +236,11 @@ func push(job string, grouping map[string]string, pushURL string, g prometheus.G
if err != nil {
return err
}
if p.useBasicAuth {
req.SetBasicAuth(p.username, p.password)
}
req.Header.Set(contentTypeHeader, string(expfmt.FmtProtoDelim))
resp, err := http.DefaultClient.Do(req)
resp, err := p.client.Do(req)
if err != nil {
return err
}
@ -133,40 +251,3 @@ func push(job string, grouping map[string]string, pushURL string, g prometheus.G
}
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.
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.
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.
func HostnameGroupingKey() map[string]string {
hostname, err := os.Hostname()
if err != nil {
return map[string]string{"instance": "unknown"}
}
return map[string]string{"instance": hostname}
}

66
prometheus/push/push_test.go
View File

@ -98,12 +98,16 @@ func TestPush(t *testing.T) {
}
wantBody := buf.Bytes()
// PushCollectors, all good.
if err := Collectors("testjob", HostnameGroupingKey(), pgwOK.URL, metric1, metric2); err != nil {
// Push some Collectors, all good.
if err := New(pgwOK.URL, "testjob").
HostnameGrouping().
Collector(metric1).
Collector(metric2).
Push(); err != nil {
t.Fatal(err)
}
if lastMethod != "PUT" {
t.Error("want method PUT for PushCollectors, got", lastMethod)
t.Error("want method PUT for Push, got", lastMethod)
}
if bytes.Compare(lastBody, wantBody) != 0 {
t.Errorf("got body %v, want %v", lastBody, wantBody)
@ -112,12 +116,15 @@ func TestPush(t *testing.T) {
t.Error("unexpected path:", lastPath)
}
// PushAddCollectors, with nil grouping, all good.
if err := AddCollectors("testjob", nil, pgwOK.URL, metric1, metric2); err != nil {
// 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 PushAddCollectors, got", lastMethod)
t.Error("want method POST for Add, got", lastMethod)
}
if bytes.Compare(lastBody, wantBody) != 0 {
t.Errorf("got body %v, want %v", lastBody, wantBody)
@ -126,8 +133,11 @@ func TestPush(t *testing.T) {
t.Error("unexpected path:", lastPath)
}
// PushCollectors with a broken PGW.
if err := Collectors("testjob", nil, pgwErr.URL, metric1, metric2); err == nil {
// 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 {
@ -135,22 +145,40 @@ func TestPush(t *testing.T) {
}
}
// PushCollectors with invalid grouping or job.
if err := Collectors("testjob", map[string]string{"foo": "bums"}, pgwErr.URL, metric1, metric2); err == nil {
// 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 := Collectors("test/job", nil, pgwErr.URL, metric1, metric2); err == nil {
if err := New(pgwOK.URL, "test/job").
Collector(metric1).
Collector(metric2).
Push(); err == nil {
t.Error("push with invalid job value succeeded")
}
if err := Collectors("testjob", map[string]string{"foo/bar": "bums"}, pgwErr.URL, metric1, metric2); err == nil {
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 := Collectors("testjob", map[string]string{"foo-bar": "bums"}, pgwErr.URL, metric1, metric2); err == nil {
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 := FromGatherer("testjob", HostnameGroupingKey(), pgwOK.URL, reg); err != nil {
if err := New(pgwOK.URL, "testjob").
HostnameGrouping().
Gatherer(reg).
Push(); err != nil {
t.Fatal(err)
}
if lastMethod != "PUT" {
@ -160,12 +188,16 @@ func TestPush(t *testing.T) {
t.Errorf("got body %v, want %v", lastBody, wantBody)
}
// PushAdd registry, all good.
if err := AddFromGatherer("testjob", map[string]string{"a": "x", "b": "y"}, pgwOK.URL, reg); err != nil {
// 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 POSTT for PushAdd, got", lastMethod)
t.Error("want method POST for Add, got", lastMethod)
}
if bytes.Compare(lastBody, wantBody) != 0 {
t.Errorf("got body %v, want %v", lastBody, wantBody)