remove loop from flush(). start/stop informers depending on k8s master

pkg/e2e/status.go

@@ -116,6 +116,15 @@ func (sm *StatusManager) startInformer() {
 	cmInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
 		UpdateFunc: func(old, cur interface{}) {
 			curCm := cur.(*v1.ConfigMap)
+			upgradeTs := curCm.Data[masterUpgradingKey]
+			// We need to pick up the master-upgrading flag here, because otherwise
+			// if the k8s master is in the process of upgrading we can't access
+			// the ConfigMap.
+			if len(upgradeTs) > 0 {
+				glog.V(2).Infof("Master upgrade began at %v", upgradeTs)
+				sm.setMasterUpgrading(upgradeTs)
+			}
+
 			if len(curCm.Data[exitKey]) > 0 {
 				glog.V(2).Infof("ConfigMap was updated with exit switch at %s", curCm.Data[exitKey])
 				close(sm.informerCh)
@@ -124,13 +133,13 @@ func (sm *StatusManager) startInformer() {
 		},
 	})
 
-	glog.V(4).Info("Started ConfigMap informer")
+	glog.V(2).Info("Started ConfigMap informer")
 	sm.informerRunning = true
 	go cmInformer.Run(sm.informerCh)
 }
 
 func (sm *StatusManager) stopInformer() {
-	glog.V(4).Info("Stopped ConfigMap informer")
+	glog.V(2).Info("Stopped ConfigMap informer")
 	sm.informerRunning = false
 	close(sm.informerCh)
 }
@@ -152,66 +161,77 @@ func (sm *StatusManager) putStatus(key string, status IngressStability) {
 	sm.cm.Data[key] = string(status)
 }
 
+func (sm *StatusManager) setMasterUpgrading(ts string) {
+	sm.f.lock.Lock()
+	defer sm.f.lock.Unlock()
+	if sm.cm.Data == nil {
+		sm.cm.Data = make(map[string]string)
+	}
+
+	sm.cm.Data[masterUpgradingKey] = ts
+}
+
 func (sm *StatusManager) masterUpgrading() bool {
 	return len(sm.cm.Data[masterUpgradingKey]) > 0
 }
 
 func (sm *StatusManager) masterUpgraded() bool {
-	if len(sm.cm.Data[masterUpgradedKey]) > 0 {
-		glog.V(4).Infof("Master has successfully upgraded at %s", sm.cm.Data[masterUpgradedKey])
-		return true
-	}
-	return false
+	return len(sm.cm.Data[masterUpgradedKey]) > 0
 }
 
 func (sm *StatusManager) flush() {
 	sm.f.lock.Lock()
 	defer sm.f.lock.Unlock()
 
+	glog.V(3).Infof("Attempting to flush %v", sm.cm.Data)
+
 	// If master is in the process of upgrading, we exit early and turn off the
 	// ConfigMap informer.
 	if sm.masterUpgrading() && sm.informerRunning {
 		sm.stopInformer()
-		return
 	}
 
 	// Restart ConfigMap informer if it was previously shut down
-	if sm.masterUpgraded() && !sm.informerRunning {
+	if !sm.informerRunning && sm.masterUpgraded() {
+		glog.V(2).Infof("Master has successfully upgraded at %s", sm.cm.Data[masterUpgradedKey])
 		sm.startInformer()
 	}
 
-	// Loop until we successfully update the config map
-	for {
-		updatedCm, err := sm.f.Clientset.Core().ConfigMaps("default").Get(configMapName, metav1.GetOptions{})
-		if err != nil {
+	// K8s considers its version of the ConfigMap to be latest, so we must get
+	// the configmap from k8s first.
+	updatedCm, err := sm.f.Clientset.Core().ConfigMaps("default").Get(configMapName, metav1.GetOptions{})
+	// The k8s API returns an empty ConfigMap upon error - we return early in
+	// order to not overwrite our ConfigMap data.
+	if err != nil {
+		// if the k8s master is upgrading, we suppress the error message because
+		// the error is expected.
+		if !sm.masterUpgrading() {
 			glog.Warningf("Error getting ConfigMap: %v", err)
 		}
 
-		if updatedCm.Data == nil {
-			updatedCm.Data = make(map[string]string)
-		}
+		glog.Warningf("Error getting ConfigMap: %v", err)
+		return
+	}
 
-		// K8s considers its version of the ConfigMap to be latest, so we must get
-		// the configmap from k8s first.
-		// We give precedence to the master-upgraded and master-upgrading flags
-		// set by the external test framework, but otherwise we prioritize
-		// Ingress statuses set by StatusManager.
-		for key, value := range sm.cm.Data {
-			if key != masterUpgradedKey && key != masterUpgradingKey {
-				updatedCm.Data[key] = value
-			}
-		}
-		sm.cm = updatedCm
-		sm.cm.Name = configMapName
-
-		_, err = sm.f.Clientset.Core().ConfigMaps("default").Update(sm.cm)
-		if err != nil {
-			glog.Warningf("Error updating ConfigMap: %v", err)
-		} else {
-			// ConfigMap successfully updated
-			break
+	if updatedCm.Data == nil {
+		updatedCm.Data = make(map[string]string)
+	}
+
+	// We give precedence to the master-upgraded and master-upgrading flags
+	// set by the external test framework, but otherwise we prioritize
+	// Ingress statuses set by StatusManager.
+	for key, value := range sm.cm.Data {
+		if key != masterUpgradedKey && key != masterUpgradingKey {
+			updatedCm.Data[key] = value
 		}
 	}
-	glog.V(3).Infof("Flushed statuses to ConfigMap")
-	glog.V(3).Infof("ConfigMap: %+v", sm.cm)
+	sm.cm = updatedCm
+	sm.cm.Name = configMapName
+
+	_, err = sm.f.Clientset.Core().ConfigMaps("default").Update(sm.cm)
+	if err != nil {
+		glog.Warningf("Error updating ConfigMap: %v", err)
+	} else {
+		glog.V(3).Infof("Flushed statuses %v to ConfigMap", sm.cm.Data)
+	}
 }