prometheus/retrieval/discovery/file_test.go
Julius Volz d88aea7e6f Fix SD mechanism source prefix handling.
The prefixed target provider changed a pointerized target group that was
reused in the wrapped target provider, causing an ever-increasing chain
of source prefixes in target groups from the Consul target provider.

We now make this bug generally impossible by switching the target group
channel from pointer to value type and thus ensuring that target groups
are copied before being passed on to other parts of the system.

I tried to not let the depointerization leak too far outside of the
channel handling (both upstream and downstream) because I tried that
initially and caused some nasty bugs, which I want to minimize.

Fixes https://github.com/prometheus/prometheus/issues/1083
2015-10-09 14:08:22 +02:00

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
}