avoid requiring runtime to be up while initializing kubelet image manager

pkg/kubelet/image_manager.go

@@ -76,6 +76,9 @@ type realImageManager struct {
 
 	// Reference to this node.
 	nodeRef *api.ObjectReference
+
+	// Track initialization
+	initialized bool
 }
 
 // Information about the images we track.
@@ -105,23 +108,24 @@ func newImageManager(runtime container.Runtime, cadvisorInterface cadvisor.Inter
 		cadvisor:     cadvisorInterface,
 		recorder:     recorder,
 		nodeRef:      nodeRef,
+		initialized:  false,
 	}
 
 	return im, nil
 }
 
 func (im *realImageManager) Start() error {
-	// Initial detection make detected time "unknown" in the past.
-	var zero time.Time
-	err := im.detectImages(zero)
-	if err != nil {
-		return err
-	}
-
 	go util.Until(func() {
-		err := im.detectImages(time.Now())
+		// Initial detection make detected time "unknown" in the past.
+		var ts time.Time
+		if im.initialized {
+			ts = time.Now()
+		}
+		err := im.detectImages(ts)
 		if err != nil {
 			glog.Warningf("[ImageManager] Failed to monitor images: %v", err)
+		} else {
+			im.initialized = true
 		}
 	}, 5*time.Minute, util.NeverStop)
 

pkg/kubelet/kubelet.go

@@ -396,10 +396,6 @@ func NewMainKubelet(
 	}
 	klet.containerManager = containerManager
 
-	// Wait for the runtime to be up with a timeout.
-	if err := waitUntilRuntimeIsUp(klet.containerRuntime, maxWaitForContainerRuntime); err != nil {
-		return nil, fmt.Errorf("timed out waiting for %q to come up: %v", containerRuntime, err)
-	}
 	klet.runtimeState.setRuntimeSync(time.Now())
 
 	klet.runner = klet.containerRuntime
@@ -429,7 +425,6 @@ func NewMainKubelet(
 
 	klet.backOff = util.NewBackOff(resyncInterval, MaxContainerBackOff)
 	klet.podKillingCh = make(chan *kubecontainer.Pod, podKillingChannelCapacity)
-
 	klet.sourcesSeen = sets.NewString()
 	return klet, nil
 }
@@ -842,12 +837,11 @@ func (kl *Kubelet) Run(updates <-chan kubetypes.PodUpdate) {
 		kl.runtimeState.setInitError(err)
 	}
 
-	go util.Until(kl.syncNetworkStatus, 30*time.Second, util.NeverStop)
 	if kl.kubeClient != nil {
 		// Start syncing node status immediately, this may set up things the runtime needs to run.
 		go util.Until(kl.syncNodeStatus, kl.nodeStatusUpdateFrequency, util.NeverStop)
 	}
-
+	go util.Until(kl.syncNetworkStatus, 30*time.Second, util.NeverStop)
 	go util.Until(kl.updateRuntimeUp, 5*time.Second, util.NeverStop)
 
 	// Start a goroutine responsible for killing pods (that are not properly