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prometheus/discovery/file/file_test.go

481 lines
11 KiB

// 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 file
import (
"context"
"encoding/json"
"io"
"os"
"path/filepath"
"sort"
"sync"
"testing"
"time"
"github.com/prometheus/common/model"
"github.com/stretchr/testify/require"
"go.uber.org/goleak"
"github.com/prometheus/prometheus/discovery/targetgroup"
)
func TestMain(m *testing.M) {
goleak.VerifyTestMain(m)
}
const defaultWait = time.Second
type testRunner struct {
*testing.T
dir string
ch chan []*targetgroup.Group
done, stopped chan struct{}
cancelSD context.CancelFunc
mtx sync.Mutex
tgs map[string]*targetgroup.Group
receivedAt time.Time
}
func newTestRunner(t *testing.T) *testRunner {
t.Helper()
return &testRunner{
T: t,
dir: t.TempDir(),
ch: make(chan []*targetgroup.Group),
done: make(chan struct{}),
stopped: make(chan struct{}),
tgs: make(map[string]*targetgroup.Group),
}
}
// copyFile atomically copies a file to the runner's directory.
func (t *testRunner) copyFile(src string) string {
t.Helper()
return t.copyFileTo(src, filepath.Base(src))
}
// copyFileTo atomically copies a file with a different name to the runner's directory.
func (t *testRunner) copyFileTo(src, name string) string {
t.Helper()
newf, err := os.CreateTemp(t.dir, "")
require.NoError(t, err)
f, err := os.Open(src)
require.NoError(t, err)
_, err = io.Copy(newf, f)
require.NoError(t, err)
require.NoError(t, f.Close())
require.NoError(t, newf.Close())
dst := filepath.Join(t.dir, name)
err = os.Rename(newf.Name(), dst)
require.NoError(t, err)
return dst
}
// writeString writes atomically a string to a file.
func (t *testRunner) writeString(file, data string) {
t.Helper()
newf, err := os.CreateTemp(t.dir, "")
require.NoError(t, err)
_, err = newf.WriteString(data)
require.NoError(t, err)
require.NoError(t, newf.Close())
err = os.Rename(newf.Name(), file)
require.NoError(t, err)
}
// appendString appends a string to a file.
func (t *testRunner) appendString(file, data string) {
t.Helper()
f, err := os.OpenFile(file, os.O_WRONLY|os.O_APPEND, 0)
require.NoError(t, err)
defer f.Close()
_, err = f.WriteString(data)
require.NoError(t, err)
}
// run starts the file SD and the loop receiving target groups updates.
func (t *testRunner) run(files ...string) {
go func() {
defer close(t.stopped)
for {
select {
case <-t.done:
os.RemoveAll(t.dir)
return
case tgs := <-t.ch:
t.mtx.Lock()
t.receivedAt = time.Now()
for _, tg := range tgs {
t.tgs[tg.Source] = tg
}
t.mtx.Unlock()
}
}
}()
for i := range files {
files[i] = filepath.Join(t.dir, files[i])
}
ctx, cancel := context.WithCancel(context.Background())
t.cancelSD = cancel
go func() {
NewDiscovery(
&SDConfig{
Files: files,
// Setting a high refresh interval to make sure that the tests only
// rely on file watches.
RefreshInterval: model.Duration(1 * time.Hour),
},
nil,
).Run(ctx, t.ch)
}()
}
func (t *testRunner) stop() {
t.cancelSD()
close(t.done)
<-t.stopped
}
func (t *testRunner) lastReceive() time.Time {
t.mtx.Lock()
defer t.mtx.Unlock()
return t.receivedAt
}
func (t *testRunner) targets() []*targetgroup.Group {
t.mtx.Lock()
defer t.mtx.Unlock()
var (
keys []string
tgs []*targetgroup.Group
)
for k := range t.tgs {
keys = append(keys, k)
}
sort.Strings(keys)
for _, k := range keys {
tgs = append(tgs, t.tgs[k])
}
return tgs
}
func (t *testRunner) requireUpdate(ref time.Time, expected []*targetgroup.Group) {
t.Helper()
for {
select {
case <-time.After(defaultWait):
t.Fatalf("Expected update but got none")
return
case <-time.After(defaultWait / 10):
if ref.Equal(t.lastReceive()) {
// No update received.
break
}
// We can receive partial updates so only check the result when the
// expected number of groups is reached.
tgs := t.targets()
if len(tgs) != len(expected) {
t.Logf("skipping update: expected %d targets, got %d", len(expected), len(tgs))
break
}
t.requireTargetGroups(expected, tgs)
if ref.After(time.Time{}) {
t.Logf("update received after %v", t.lastReceive().Sub(ref))
}
return
}
}
}
func (t *testRunner) requireTargetGroups(expected, got []*targetgroup.Group) {
t.Helper()
b1, err := json.Marshal(expected)
if err != nil {
panic(err)
}
b2, err := json.Marshal(got)
if err != nil {
panic(err)
}
require.Equal(t, string(b1), string(b2))
}
// validTg() maps to fixtures/valid.{json,yml}.
func validTg(file string) []*targetgroup.Group {
return []*targetgroup.Group{
{
Targets: []model.LabelSet{
{
model.AddressLabel: model.LabelValue("localhost:9090"),
},
{
model.AddressLabel: model.LabelValue("example.org:443"),
},
},
Labels: model.LabelSet{
model.LabelName("foo"): model.LabelValue("bar"),
fileSDFilepathLabel: model.LabelValue(file),
},
Source: fileSource(file, 0),
},
{
Targets: []model.LabelSet{
{
model.AddressLabel: model.LabelValue("my.domain"),
},
},
Labels: model.LabelSet{
fileSDFilepathLabel: model.LabelValue(file),
},
Source: fileSource(file, 1),
},
}
}
// valid2Tg() maps to fixtures/valid2.{json,yml}.
func valid2Tg(file string) []*targetgroup.Group {
return []*targetgroup.Group{
{
Targets: []model.LabelSet{
{
model.AddressLabel: model.LabelValue("my.domain"),
},
},
Labels: model.LabelSet{
fileSDFilepathLabel: model.LabelValue(file),
},
Source: fileSource(file, 0),
},
{
Targets: []model.LabelSet{
{
model.AddressLabel: model.LabelValue("localhost:9090"),
},
},
Labels: model.LabelSet{
model.LabelName("foo"): model.LabelValue("bar"),
model.LabelName("fred"): model.LabelValue("baz"),
fileSDFilepathLabel: model.LabelValue(file),
},
Source: fileSource(file, 1),
},
{
Targets: []model.LabelSet{
{
model.AddressLabel: model.LabelValue("example.org:443"),
},
},
Labels: model.LabelSet{
model.LabelName("scheme"): model.LabelValue("https"),
fileSDFilepathLabel: model.LabelValue(file),
},
Source: fileSource(file, 2),
},
}
}
func TestInitialUpdate(t *testing.T) {
for _, tc := range []string{
"fixtures/valid.yml",
"fixtures/valid.json",
} {
tc := tc
t.Run(tc, func(t *testing.T) {
t.Parallel()
runner := newTestRunner(t)
sdFile := runner.copyFile(tc)
runner.run("*" + filepath.Ext(tc))
defer runner.stop()
// Verify that we receive the initial target groups.
runner.requireUpdate(time.Time{}, validTg(sdFile))
})
}
}
func TestInvalidFile(t *testing.T) {
for _, tc := range []string{
"fixtures/invalid_nil.yml",
"fixtures/invalid_nil.json",
} {
tc := tc
t.Run(tc, func(t *testing.T) {
t.Parallel()
now := time.Now()
runner := newTestRunner(t)
runner.copyFile(tc)
runner.run("*" + filepath.Ext(tc))
defer runner.stop()
// Verify that we've received nothing.
time.Sleep(defaultWait)
if runner.lastReceive().After(now) {
t.Fatalf("unexpected targets received: %v", runner.targets())
}
})
}
}
func TestNoopFileUpdate(t *testing.T) {
t.Parallel()
runner := newTestRunner(t)
sdFile := runner.copyFile("fixtures/valid.yml")
runner.run("*.yml")
defer runner.stop()
// Verify that we receive the initial target groups.
runner.requireUpdate(time.Time{}, validTg(sdFile))
// Verify that we receive an update with the same target groups.
ref := runner.lastReceive()
runner.copyFileTo("fixtures/valid3.yml", "valid.yml")
runner.requireUpdate(ref, validTg(sdFile))
}
func TestFileUpdate(t *testing.T) {
t.Parallel()
runner := newTestRunner(t)
sdFile := runner.copyFile("fixtures/valid.yml")
runner.run("*.yml")
defer runner.stop()
// Verify that we receive the initial target groups.
runner.requireUpdate(time.Time{}, validTg(sdFile))
// Verify that we receive an update with the new target groups.
ref := runner.lastReceive()
runner.copyFileTo("fixtures/valid2.yml", "valid.yml")
runner.requireUpdate(ref, valid2Tg(sdFile))
}
func TestInvalidFileUpdate(t *testing.T) {
t.Parallel()
runner := newTestRunner(t)
sdFile := runner.copyFile("fixtures/valid.yml")
runner.run("*.yml")
defer runner.stop()
// Verify that we receive the initial target groups.
runner.requireUpdate(time.Time{}, validTg(sdFile))
ref := runner.lastReceive()
runner.writeString(sdFile, "]gibberish\n][")
// Verify that we receive nothing or the same targets as before.
time.Sleep(defaultWait)
if runner.lastReceive().After(ref) {
runner.requireTargetGroups(validTg(sdFile), runner.targets())
}
}
func TestUpdateFileWithPartialWrites(t *testing.T) {
t.Parallel()
runner := newTestRunner(t)
sdFile := runner.copyFile("fixtures/valid.yml")
runner.run("*.yml")
defer runner.stop()
// Verify that we receive the initial target groups.
runner.requireUpdate(time.Time{}, validTg(sdFile))
// Do a partial write operation.
ref := runner.lastReceive()
runner.writeString(sdFile, "- targets")
time.Sleep(defaultWait)
// Verify that we receive nothing or the same target groups as before.
if runner.lastReceive().After(ref) {
runner.requireTargetGroups(validTg(sdFile), runner.targets())
}
// Verify that we receive the update target groups once the file is a valid YAML payload.
ref = runner.lastReceive()
runner.appendString(sdFile, `: ["localhost:9091"]`)
runner.requireUpdate(ref,
[]*targetgroup.Group{
{
Targets: []model.LabelSet{
{
model.AddressLabel: model.LabelValue("localhost:9091"),
},
},
Labels: model.LabelSet{
fileSDFilepathLabel: model.LabelValue(sdFile),
},
Source: fileSource(sdFile, 0),
},
{
Source: fileSource(sdFile, 1),
},
},
)
}
func TestRemoveFile(t *testing.T) {
t.Parallel()
runner := newTestRunner(t)
sdFile := runner.copyFile("fixtures/valid.yml")
runner.run("*.yml")
defer runner.stop()
// Verify that we receive the initial target groups.
runner.requireUpdate(time.Time{}, validTg(sdFile))
// Verify that we receive the update about the target groups being removed.
ref := runner.lastReceive()
require.NoError(t, os.Remove(sdFile))
runner.requireUpdate(
ref,
[]*targetgroup.Group{
{
Source: fileSource(sdFile, 0),
},
{
Source: fileSource(sdFile, 1),
},
},
)
}