prometheus/retrieval/discovery/file_test.go

111 lines
2.6 KiB
Go

package discovery
import (
"fmt"
"io"
"os"
"testing"
"time"
"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 = config.Duration(1 * time.Hour)
var (
fsd = NewFileDiscovery(&conf)
ch = make(chan *config.TargetGroup)
done = make(chan struct{})
)
go fsd.Run(ch, done)
select {
case <-time.After(25 * time.Millisecond):
// Expected.
case tg := <-ch:
t.Fatalf("Unexpected target group in file discovery: %s", tg)
}
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()
// The files contain two target groups which are read and sent in order.
select {
case <-time.After(15 * time.Second):
t.Fatalf("Expected new target group but got none")
case tg := <-ch:
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)
}
}
select {
case <-time.After(15 * time.Second):
t.Fatalf("Expected new target group but got none")
case tg := <-ch:
if tg.String() != fmt.Sprintf("fixtures/_test%s:1", ext) {
t.Fatalf("Unexpected target group %s", tg)
}
}
// 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 tg := 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(tg.Targets) == 0 {
t.Errorf("Unexpected empty target group received: %s", tg)
}
}
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)
close(done)
<-drained
}