fix cns zap logger issue

Author: paulyufan

cns/logger/cnslogger.go

@@ -45,7 +45,12 @@ func New(fileName string, logLevel, logTarget int, logDir string) (loggershim, e
 	if err != nil {
 		l.Errorf("Failed to get zap Platform cores: %v", err)
 	}
-	zapLogger := zap.New(platformCore, zap.AddCaller()).With(zap.Int("pid", os.Getpid()))
+	
+    zapLogger := zap.New(
+		platformCore,
+		zap.AddCaller(),
+		zap.AddStacktrace(zapcore.WarnLevel), 
+	).With(zap.Int("pid", os.Getpid()))
 
 	return &logger{
 		logger:    l,

cns/restserver/metrics.go

@@ -219,7 +219,7 @@ func (a *asyncMetricsRecorder) record() {
 func (service *HTTPRestService) publishIPStateMetrics() {
 	recorder.once.Do(func() {
 		recorder.podIPConfigSrc = service.PodIPConfigStates
-		recorder.sig = make(chan struct{})
+		recorder.sig = make(chan struct{}, 1)
 		go recorder.run()
 	})
 	select {