Add more Go leak tests (#7652)

* Implement go leak test for promql

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

* Implement go leak test for Consul SD

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

* Implement go leak test in discovery manager

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

discovery/consul/consul_test.go

@@ -26,8 +26,13 @@ import (
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
 	"github.com/prometheus/prometheus/util/testutil"
+	"go.uber.org/goleak"
 )
 
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}
+
 func TestConfiguredService(t *testing.T) {
 	conf := &SDConfig{
 		Services: []string{"configuredServiceName"}}
@@ -283,10 +288,14 @@ func TestAllServices(t *testing.T) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	ch := make(chan []*targetgroup.Group)
-	go d.Run(ctx, ch)
+	go func() {
+		d.Run(ctx, ch)
+		close(ch)
+	}()
 	checkOneTarget(t, <-ch)
 	checkOneTarget(t, <-ch)
 	cancel()
+	<-ch
 }
 
 // Watch only the test service.
@@ -319,9 +328,13 @@ func TestAllOptions(t *testing.T) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	ch := make(chan []*targetgroup.Group)
-	go d.Run(ctx, ch)
+	go func() {
+		d.Run(ctx, ch)
+		close(ch)
+	}()
 	checkOneTarget(t, <-ch)
 	cancel()
+	<-ch
 }
 
 func TestGetDatacenterShouldReturnError(t *testing.T) {

discovery/manager_test.go

@@ -25,7 +25,7 @@ import (
 	"time"
 
 	"github.com/go-kit/kit/log"
-	"github.com/prometheus/client_golang/prometheus/testutil"
+	client_testutil "github.com/prometheus/client_golang/prometheus/testutil"
 	common_config "github.com/prometheus/common/config"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/config"
@@ -33,9 +33,14 @@ import (
 	"github.com/prometheus/prometheus/discovery/consul"
 	"github.com/prometheus/prometheus/discovery/file"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
+	"github.com/prometheus/prometheus/util/testutil"
 	"gopkg.in/yaml.v2"
 )
 
+func TestMain(m *testing.M) {
+	testutil.TolerantVerifyLeak(m)
+}
+
 // TestTargetUpdatesOrder checks that the target updates are received in the expected order.
 func TestTargetUpdatesOrder(t *testing.T) {
 
@@ -984,7 +989,7 @@ func TestGaugeFailedConfigs(t *testing.T) {
 	discoveryManager.ApplyConfig(c)
 	<-discoveryManager.SyncCh()
 
-	failedCount := testutil.ToFloat64(failedConfigs)
+	failedCount := client_testutil.ToFloat64(failedConfigs)
 	if failedCount != 3 {
 		t.Fatalf("Expected to have 3 failed configs, got: %v", failedCount)
 	}
@@ -1004,7 +1009,7 @@ func TestGaugeFailedConfigs(t *testing.T) {
 	discoveryManager.ApplyConfig(c)
 	<-discoveryManager.SyncCh()
 
-	failedCount = testutil.ToFloat64(failedConfigs)
+	failedCount = client_testutil.ToFloat64(failedConfigs)
 	if failedCount != 0 {
 		t.Fatalf("Expected to get no failed config, got: %v", failedCount)
 	}

promql/engine_test.go

@@ -28,8 +28,13 @@ import (
 	"github.com/prometheus/prometheus/promql/parser"
 	"github.com/prometheus/prometheus/storage"
 	"github.com/prometheus/prometheus/util/testutil"
+	"go.uber.org/goleak"
 )
 
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}
+
 func TestQueryConcurrency(t *testing.T) {
 	maxConcurrency := 10
 

util/testutil/testing.go

@@ -25,9 +25,11 @@ package testutil
 import (
 	"fmt"
 	"reflect"
+	"testing"
 
 	"github.com/davecgh/go-spew/spew"
 	"github.com/pmezard/go-difflib/difflib"
+	"go.uber.org/goleak"
 )
 
 // This package is imported by non-test code and therefore cannot import the
@@ -154,3 +156,14 @@ func formatMessage(msgAndArgs []interface{}) string {
 	}
 	return ""
 }
+
+// TolerantVerifyLeak verifies go leaks but excludes the go routines that are
+// launched as side effects of some of our dependencies.
+func TolerantVerifyLeak(m *testing.M) {
+	goleak.VerifyTestMain(m,
+		// https://github.com/census-instrumentation/opencensus-go/blob/d7677d6af5953e0506ac4c08f349c62b917a443a/stats/view/worker.go#L34
+		goleak.IgnoreTopFunction("go.opencensus.io/stats/view.(*worker).start"),
+		// https://github.com/kubernetes/klog/blob/c85d02d1c76a9ebafa81eb6d35c980734f2c4727/klog.go#L417
+		goleak.IgnoreTopFunction("k8s.io/klog/v2.(*loggingT).flushDaemon"),
+	)
+}