Add unit test for goroutine leak.

pkg/systemlogmonitor/log_monitor_test.go

@@ -17,10 +17,15 @@ limitations under the License.
 package systemlogmonitor
 
 import (
+	"fmt"
 	"reflect"
+	"runtime"
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/assert"
+
+	watchertest "k8s.io/node-problem-detector/pkg/systemlogmonitor/logwatchers/testing"
 	logtypes "k8s.io/node-problem-detector/pkg/systemlogmonitor/types"
 	"k8s.io/node-problem-detector/pkg/types"
 )
@@ -131,3 +136,13 @@ func TestGenerateStatus(t *testing.T) {
 		}
 	}
 }
+
+func TestGoroutineLeak(t *testing.T) {
+	orignal := runtime.NumGoroutine()
+	f := watchertest.NewFakeLogWatcher(10)
+	f.InjectError(fmt.Errorf("unexpected error"))
+	l := &logMonitor{watcher: f}
+	_, err := l.Start()
+	assert.Error(t, err)
+	assert.Equal(t, orignal, runtime.NumGoroutine())
+}

pkg/systemlogmonitor/logwatchers/filelog/log_watcher_test.go

@@ -19,6 +19,7 @@ package filelog
 import (
 	"io/ioutil"
 	"os"
+	"runtime"
 	"testing"
 	"time"
 
@@ -170,3 +171,16 @@ Jan  2 03:04:05 kernel: [2.000000] 3
 		}
 	}
 }
+
+func TestGoroutineLeak(t *testing.T) {
+	orignal := runtime.NumGoroutine()
+	w := NewSyslogWatcherOrDie(types.WatcherConfig{
+		Plugin:       "filelog",
+		PluginConfig: getTestPluginConfig(),
+		LogPath:      "/not/exist/path",
+		Lookback:     "10m",
+	})
+	_, err := w.Watch()
+	assert.Error(t, err)
+	assert.Equal(t, orignal, runtime.NumGoroutine())
+}

pkg/systemlogmonitor/logwatchers/journald/log_watcher_test.go

@@ -19,12 +19,14 @@ limitations under the License.
 package journald
 
 import (
+	"runtime"
 	"testing"
 	"time"
 
 	"github.com/coreos/go-systemd/sdjournal"
 	"github.com/stretchr/testify/assert"
 
+	"k8s.io/node-problem-detector/pkg/systemlogmonitor/logwatchers/types"
 	logtypes "k8s.io/node-problem-detector/pkg/systemlogmonitor/types"
 )
 
@@ -62,3 +64,16 @@ func TestTranslate(t *testing.T) {
 		assert.Equal(t, test.log, translate(test.entry))
 	}
 }
+
+func TestGoroutineLeak(t *testing.T) {
+	orignal := runtime.NumGoroutine()
+	w := NewJournaldWatcher(types.WatcherConfig{
+		Plugin:       "journald",
+		PluginConfig: map[string]string{"source": "not-exist-service"},
+		LogPath:      "/not/exist/path",
+		Lookback:     "10m",
+	})
+	_, err := w.Watch()
+	assert.Error(t, err)
+	assert.Equal(t, orignal, runtime.NumGoroutine())
+}

pkg/systemlogmonitor/logwatchers/testing/fake_log_watcher.go

@@ -0,0 +1,59 @@
+/*
+Copyright 2017 The Kubernetes Authors All rights reserved.
+
+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 testing
+
+import (
+	"sync"
+
+	"k8s.io/node-problem-detector/pkg/systemlogmonitor/logwatchers/types"
+	logtypes "k8s.io/node-problem-detector/pkg/systemlogmonitor/types"
+)
+
+// FakeLogWatcher is a fake mock of log watcher.
+type FakeLogWatcher struct {
+	sync.Mutex
+	buf chan *logtypes.Log
+	err error
+}
+
+var _ types.LogWatcher = &FakeLogWatcher{}
+
+func NewFakeLogWatcher(bufferSize int) *FakeLogWatcher {
+	return &FakeLogWatcher{buf: make(chan *logtypes.Log, bufferSize)}
+}
+
+// InjectLog injects a fake log into the watch channel
+func (f *FakeLogWatcher) InjectLog(log *logtypes.Log) {
+	f.buf <- log
+}
+
+// InjectError injects an error of Watch function.
+func (f *FakeLogWatcher) InjectError(err error) {
+	f.Lock()
+	defer f.Unlock()
+	f.err = err
+}
+
+// Watch is the fake watch function.
+func (f *FakeLogWatcher) Watch() (<-chan *logtypes.Log, error) {
+	return f.buf, f.err
+}
+
+// Stop is the fake stop function.
+func (f *FakeLogWatcher) Stop() {
+	close(f.buf)
+}