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prometheus/retrieval/discovery/file_test.go

135 lines
3.3 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 discovery
import (
"fmt"
"io"
"os"
"testing"
"time"
"github.com/prometheus/common/model"
"golang.org/x/net/context"
"github.com/prometheus/prometheus/config"
)
func TestFileSD(t *testing.T) {
defer os.Remove("fixtures/_test.yml")
defer os.Remove("fixtures/_test.json")
testFileSD(t, ".yml")
testFileSD(t, ".json")
}
func testFileSD(t *testing.T, ext string) {
// As interval refreshing is more of a fallback, we only want to test
// whether file watches work as expected.
var conf config.FileSDConfig
conf.Names = []string{"fixtures/_*" + ext}
conf.RefreshInterval = model.Duration(1 * time.Hour)
var (
fsd = NewFileDiscovery(&conf)
ch = make(chan []*config.TargetGroup)
ctx, cancel = context.WithCancel(context.Background())
)
go fsd.Run(ctx, ch)
select {
case <-time.After(25 * time.Millisecond):
// Expected.
case tgs := <-ch:
t.Fatalf("Unexpected target groups in file discovery: %s", tgs)
}
newf, err := os.Create("fixtures/_test" + ext)
if err != nil {
t.Fatal(err)
}
defer newf.Close()
f, err := os.Open("fixtures/target_groups" + ext)
if err != nil {
t.Fatal(err)
}
defer f.Close()
_, err = io.Copy(newf, f)
if err != nil {
t.Fatal(err)
}
newf.Close()
timeout := time.After(15 * time.Second)
// The files contain two target groups.
retry:
for {
select {
case <-timeout:
t.Fatalf("Expected new target group but got none")
case tgs := <-ch:
if len(tgs) != 2 {
continue retry // Potentially a partial write, just retry.
}
tg := tgs[0]
if _, ok := tg.Labels["foo"]; !ok {
t.Fatalf("Label not parsed")
}
if tg.String() != fmt.Sprintf("fixtures/_test%s:0", ext) {
t.Fatalf("Unexpected target group %s", tg)
}
tg = tgs[1]
if tg.String() != fmt.Sprintf("fixtures/_test%s:1", ext) {
t.Fatalf("Unexpected target groups %s", tg)
}
break retry
}
}
// Based on unknown circumstances, sometimes fsnotify will trigger more events in
// some runs (which might be empty, chains of different operations etc.).
// We have to drain those (as the target manager would) to avoid deadlocking and must
// not try to make sense of it all...
drained := make(chan struct{})
go func() {
for tgs := range ch {
// Below we will change the file to a bad syntax. Previously extracted target
// groups must not be deleted via sending an empty target group.
if len(tgs[0].Targets) == 0 {
t.Errorf("Unexpected empty target groups received: %s", tgs)
}
}
close(drained)
}()
newf, err = os.Create("fixtures/_test.new")
if err != nil {
t.Fatal(err)
}
defer os.Remove(newf.Name())
if _, err := newf.Write([]byte("]gibberish\n][")); err != nil {
t.Fatal(err)
}
newf.Close()
os.Rename(newf.Name(), "fixtures/_test"+ext)
cancel()
<-drained
}