[Bugfix] Fix After leaked GoRoutines (#1231)

Author: ajanikow

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [master](https://github.com/arangodb/kube-arangodb/tree/master) (N/A)
 - (Bugfix) Fix deployment creation on ARM64
 - (DebugPackage) Add Agency Dump & State
+- (Bugfix) Fix After leaked GoRoutines
 
 ## [1.2.23](https://github.com/arangodb/kube-arangodb/tree/1.2.23) (2023-01-12)
 - (Bugfix) Remove PDBs if group count is 0

pkg/util/timer/after.go

@@ -1,7 +1,7 @@
 //
 // DISCLAIMER
 //
-// Copyright 2016-2022 ArangoDB GmbH, Cologne, Germany
+// Copyright 2016-2023 ArangoDB GmbH, Cologne, Germany
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -23,7 +23,7 @@ package timer
 import "time"
 
 func After(duration time.Duration) <-chan time.Time {
-	r := make(chan time.Time)
+	r := make(chan time.Time, 1)
 
 	go func() {
 		defer close(r)

pkg/util/timer/after_leak_test.go

@@ -0,0 +1,45 @@
+//
+// DISCLAIMER
+//
+// Copyright 2023 ArangoDB GmbH, Cologne, Germany
+//
+// 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.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+
+package timer
+
+import (
+	"runtime"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func checkGoRoutinesLeak(t *testing.T, f func()) {
+	got := runtime.NumGoroutine()
+
+	f()
+
+	require.Equal(t, got, runtime.NumGoroutine())
+}
+
+func Test_AfterLeaks(t *testing.T) {
+	checkGoRoutinesLeak(t, func() {
+		After(time.Second)
+
+		time.Sleep(5 * time.Second)
+	})
+}