// Run begins watching and syncing daemon sets.
func (dsc *DaemonSetsController) Run(workers int, stopCh <-chan struct{}) {
	defer utilruntime.HandleCrash()
	defer dsc.queue.ShutDown()

	glog.Infof("Starting Daemon Sets controller manager")
	go dsc.dsController.Run(stopCh)
	go dsc.podController.Run(stopCh)
	go dsc.nodeController.Run(stopCh)

	if !framework.WaitForCacheSync(stopCh, dsc.podStoreSynced, dsc.nodeStoreSynced) {
		return
	}

	for i := 0; i < workers; i++ {
		go wait.Until(dsc.runWorker, time.Second, stopCh)
	}

	if dsc.internalPodInformer != nil {
		go dsc.internalPodInformer.Run(stopCh)
	}

	<-stopCh
	glog.Infof("Shutting down Daemon Set Controller")
}
// Run starts an asynchronous loop that monitors the status of cluster nodes.
func (nc *NodeController) Run() {
	go nc.nodeController.Run(wait.NeverStop)
	go nc.podController.Run(wait.NeverStop)
	go nc.daemonSetController.Run(wait.NeverStop)
	if nc.internalPodInformer != nil {
		go nc.internalPodInformer.Run(wait.NeverStop)
	}

	go func() {
		defer utilruntime.HandleCrash()

		if !framework.WaitForCacheSync(wait.NeverStop, nc.nodeController.HasSynced, nc.podController.HasSynced, nc.daemonSetController.HasSynced) {
			utilruntime.HandleError(errors.New("NodeController timed out while waiting for informers to sync..."))
			return
		}

		// Incorporate the results of node status pushed from kubelet to master.
		go wait.Until(func() {
			if err := nc.monitorNodeStatus(); err != nil {
				glog.Errorf("Error monitoring node status: %v", err)
			}
		}, nc.nodeMonitorPeriod, wait.NeverStop)

		// Managing eviction of nodes:
		// 1. when we delete pods off a node, if the node was not empty at the time we then
		//    queue a termination watcher
		//    a. If we hit an error, retry deletion
		// 2. The terminator loop ensures that pods are eventually cleaned and we never
		//    terminate a pod in a time period less than nc.maximumGracePeriod. AddedAt
		//    is the time from which we measure "has this pod been terminating too long",
		//    after which we will delete the pod with grace period 0 (force delete).
		//    a. If we hit errors, retry instantly
		//    b. If there are no pods left terminating, exit
		//    c. If there are pods still terminating, wait for their estimated completion
		//       before retrying
		go wait.Until(func() {
			nc.evictorLock.Lock()
			defer nc.evictorLock.Unlock()
			for k := range nc.zonePodEvictor {
				nc.zonePodEvictor[k].Try(func(value TimedValue) (bool, time.Duration) {
					obj, exists, err := nc.nodeStore.GetByKey(value.Value)
					if err != nil {
						glog.Warningf("Failed to get Node %v from the nodeStore: %v", value.Value, err)
					} else if !exists {
						glog.Warningf("Node %v no longer present in nodeStore!", value.Value)
					} else {
						node, _ := obj.(*api.Node)
						zone := utilnode.GetZoneKey(node)
						EvictionsNumber.WithLabelValues(zone).Inc()
					}

					nodeUid, _ := value.UID.(string)
					remaining, err := deletePods(nc.kubeClient, nc.recorder, value.Value, nodeUid, nc.daemonSetStore)
					if err != nil {
						utilruntime.HandleError(fmt.Errorf("unable to evict node %q: %v", value.Value, err))
						return false, 0
					}

					if remaining {
						nc.zoneTerminationEvictor[k].Add(value.Value, value.UID)
					}
					return true, 0
				})
			}
		}, nodeEvictionPeriod, wait.NeverStop)

		// TODO: replace with a controller that ensures pods that are terminating complete
		// in a particular time period
		go wait.Until(func() {
			nc.evictorLock.Lock()
			defer nc.evictorLock.Unlock()
			for k := range nc.zoneTerminationEvictor {
				nc.zoneTerminationEvictor[k].Try(func(value TimedValue) (bool, time.Duration) {
					nodeUid, _ := value.UID.(string)
					completed, remaining, err := terminatePods(nc.kubeClient, nc.recorder, value.Value, nodeUid, value.AddedAt, nc.maximumGracePeriod)
					if err != nil {
						utilruntime.HandleError(fmt.Errorf("unable to terminate pods on node %q: %v", value.Value, err))
						return false, 0
					}

					if completed {
						glog.V(2).Infof("All pods terminated on %s", value.Value)
						recordNodeEvent(nc.recorder, value.Value, nodeUid, api.EventTypeNormal, "TerminatedAllPods", fmt.Sprintf("Terminated all Pods on Node %s.", value.Value))
						return true, 0
					}

					glog.V(2).Infof("Pods terminating since %s on %q, estimated completion %s", value.AddedAt, value.Value, remaining)
					// clamp very short intervals
					if remaining < nodeEvictionPeriod {
						remaining = nodeEvictionPeriod
					}
					return false, remaining
				})
			}
		}, nodeEvictionPeriod, wait.NeverStop)

		go wait.Until(func() {
			pods, err := nc.podStore.List(labels.Everything())
			if err != nil {
				utilruntime.HandleError(err)
				return
			}
			cleanupOrphanedPods(pods, nc.nodeStore.Store, nc.forcefullyDeletePod)
		}, 30*time.Second, wait.NeverStop)
	}()
}