Merge pull request #12959 from smarterclayton/handle_pods_in_kubelet

Support graceful termination in the Kubelet (5/7)

pkg/kubelet/config/config.go

@@ -217,9 +217,8 @@ func (s *podStorage) merge(source string, change interface{}) (adds, updates, de
 		for _, ref := range filtered {
 			name := kubecontainer.GetPodFullName(ref)
 			if existing, found := pods[name]; found {
-				if !reflect.DeepEqual(existing.Spec, ref.Spec) {
+				if checkAndUpdatePod(existing, ref) {
 					// this is an update
-					existing.Spec = ref.Spec
 					updates.Pods = append(updates.Pods, existing)
 					continue
 				}
@@ -261,9 +260,8 @@ func (s *podStorage) merge(source string, change interface{}) (adds, updates, de
 			name := kubecontainer.GetPodFullName(ref)
 			if existing, found := oldPods[name]; found {
 				pods[name] = existing
-				if !reflect.DeepEqual(existing.Spec, ref.Spec) {
+				if checkAndUpdatePod(existing, ref) {
 					// this is an update
-					existing.Spec = ref.Spec
 					updates.Pods = append(updates.Pods, existing)
 					continue
 				}
@@ -335,6 +333,23 @@ func filterInvalidPods(pods []*api.Pod, source string, recorder record.EventReco
 	return
 }
 
+// checkAndUpdatePod updates existing if ref makes a meaningful change and returns true, or
+// returns false if there was no update.
+func checkAndUpdatePod(existing, ref *api.Pod) bool {
+	// TODO: it would be better to update the whole object and only preserve certain things
+	//       like the source annotation or the UID (to ensure safety)
+	if reflect.DeepEqual(existing.Spec, ref.Spec) &&
+		reflect.DeepEqual(existing.DeletionTimestamp, ref.DeletionTimestamp) &&
+		reflect.DeepEqual(existing.DeletionGracePeriodSeconds, ref.DeletionGracePeriodSeconds) {
+		return false
+	}
+	// this is an update
+	existing.Spec = ref.Spec
+	existing.DeletionTimestamp = ref.DeletionTimestamp
+	existing.DeletionGracePeriodSeconds = ref.DeletionGracePeriodSeconds
+	return true
+}
+
 // Sync sends a copy of the current state through the update channel.
 func (s *podStorage) Sync() {
 	s.updateLock.Lock()

pkg/kubelet/container/fake_runtime.go

@@ -163,13 +163,13 @@ func (f *FakeRuntime) SyncPod(pod *api.Pod, _ Pod, _ api.PodStatus, _ []api.Secr
 	return f.Err
 }
 
-func (f *FakeRuntime) KillPod(pod Pod) error {
+func (f *FakeRuntime) KillPod(pod *api.Pod, runningPod Pod) error {
 	f.Lock()
 	defer f.Unlock()
 
 	f.CalledFunctions = append(f.CalledFunctions, "KillPod")
-	f.KilledPods = append(f.KilledPods, string(pod.ID))
-	for _, c := range pod.Containers {
+	f.KilledPods = append(f.KilledPods, string(runningPod.ID))
+	for _, c := range runningPod.Containers {
 		f.KilledContainers = append(f.KilledContainers, c.Name)
 	}
 	return f.Err

pkg/kubelet/container/runtime.go

@@ -54,8 +54,8 @@ type Runtime interface {
 	GetPods(all bool) ([]*Pod, error)
 	// Syncs the running pod into the desired pod.
 	SyncPod(pod *api.Pod, runningPod Pod, podStatus api.PodStatus, pullSecrets []api.Secret) error
-	// KillPod kills all the containers of a pod.
-	KillPod(pod Pod) error
+	// KillPod kills all the containers of a pod. Pod may be nil, running pod must not be.
+	KillPod(pod *api.Pod, runningPod Pod) error
 	// GetPodStatus retrieves the status of the pod, including the information of
 	// all containers in the pod. Clients of this interface assume the containers
 	// statuses in a pod always have a deterministic ordering (eg: sorted by name).

pkg/kubelet/dockertools/manager.go

@@ -56,12 +56,21 @@ import (
 const (
 	maxReasonCacheEntries = 200
 
-	kubernetesPodLabel       = "io.kubernetes.pod.data"
-	kubernetesContainerLabel = "io.kubernetes.container.name"
 	// ndots specifies the minimum number of dots that a domain name must contain for the resolver to consider it as FQDN (fully-qualified)
 	// we want to able to consider SRV lookup names like _dns._udp.kube-dns.default.svc to be considered relative.
 	// hence, setting ndots to be 5.
 	ndotsDNSOption = "options ndots:5\n"
+	// In order to avoid unnecessary SIGKILLs, give every container a minimum grace
+	// period after SIGTERM. Docker will guarantee the termination, but SIGTERM is
+	// potentially dangerous.
+	// TODO: evaluate whether there are scenarios in which SIGKILL is preferable to
+	// SIGTERM for certain process types, which may justify setting this to 0.
+	minimumGracePeriodInSeconds = 2
+
+	kubernetesNameLabel                   = "io.kubernetes.pod.name"
+	kubernetesPodLabel                    = "io.kubernetes.pod.data"
+	kubernetesTerminationGracePeriodLabel = "io.kubernetes.pod.terminationGracePeriod"
+	kubernetesContainerLabel              = "io.kubernetes.container.name"
 )
 
 // DockerManager implements the Runtime interface.
@@ -589,12 +598,19 @@ func (dm *DockerManager) runContainer(
 	if len(containerHostname) > hostnameMaxLen {
 		containerHostname = containerHostname[:hostnameMaxLen]
 	}
+
+	// Pod information is recorded on the container as labels to preserve it in the event the pod is deleted
+	// while the Kubelet is down and there is no information available to recover the pod. This includes
+	// termination information like the termination grace period and the pre stop hooks.
+	// TODO: keep these labels up to date if the pod changes
 	namespacedName := types.NamespacedName{Namespace: pod.Namespace, Name: pod.Name}
 	labels := map[string]string{
-		"io.kubernetes.pod.name": namespacedName.String(),
+		kubernetesNameLabel: namespacedName.String(),
+	}
+	if pod.Spec.TerminationGracePeriodSeconds != nil {
+		labels[kubernetesTerminationGracePeriodLabel] = strconv.FormatInt(*pod.Spec.TerminationGracePeriodSeconds, 10)
 	}
 	if container.Lifecycle != nil && container.Lifecycle.PreStop != nil {
-		glog.V(1).Infof("Setting preStop hook")
 		// TODO: This is kind of hacky, we should really just encode the bits we need.
 		data, err := latest.Codec.Encode(pod)
 		if err != nil {
@@ -1106,40 +1122,56 @@ func (dm *DockerManager) PortForward(pod *kubecontainer.Pod, port uint16, stream
 }
 
 // Kills all containers in the specified pod
-func (dm *DockerManager) KillPod(pod kubecontainer.Pod) error {
+func (dm *DockerManager) KillPod(pod *api.Pod, runningPod kubecontainer.Pod) error {
 	// Send the kills in parallel since they may take a long time. Len + 1 since there
 	// can be Len errors + the networkPlugin teardown error.
-	errs := make(chan error, len(pod.Containers)+1)
+	errs := make(chan error, len(runningPod.Containers)+1)
 	wg := sync.WaitGroup{}
-	var networkID types.UID
-	for _, container := range pod.Containers {
+	var (
+		networkContainer *kubecontainer.Container
+		networkSpec      *api.Container
+	)
+	for _, container := range runningPod.Containers {
 		wg.Add(1)
 		go func(container *kubecontainer.Container) {
 			defer util.HandleCrash()
 			defer wg.Done()
 
+			var containerSpec *api.Container
+			if pod != nil {
+				for i, c := range pod.Spec.Containers {
+					if c.Name == container.Name {
+						containerSpec = &pod.Spec.Containers[i]
+						break
+					}
+				}
+			}
+
 			// TODO: Handle this without signaling the pod infra container to
 			// adapt to the generic container runtime.
 			if container.Name == PodInfraContainerName {
 				// Store the container runtime for later deletion.
 				// We do this so that PreStop handlers can run in the network namespace.
-				networkID = container.ID
+				networkContainer = container
+				networkSpec = containerSpec
 				return
 			}
-			if err := dm.killContainer(container.ID); err != nil {
-				glog.Errorf("Failed to delete container: %v; Skipping pod %q", err, pod.ID)
+
+			err := dm.KillContainerInPod(container.ID, containerSpec, pod)
+			if err != nil {
+				glog.Errorf("Failed to delete container: %v; Skipping pod %q", err, runningPod.ID)
 				errs <- err
 			}
 		}(container)
 	}
 	wg.Wait()
-	if len(networkID) > 0 {
-		if err := dm.networkPlugin.TearDownPod(pod.Namespace, pod.Name, kubeletTypes.DockerID(networkID)); err != nil {
+	if networkContainer != nil {
+		if err := dm.networkPlugin.TearDownPod(runningPod.Namespace, runningPod.Name, kubeletTypes.DockerID(networkContainer.ID)); err != nil {
 			glog.Errorf("Failed tearing down the infra container: %v", err)
 			errs <- err
 		}
-		if err := dm.killContainer(networkID); err != nil {
-			glog.Errorf("Failed to delete container: %v; Skipping pod %q", err, pod.ID)
+		if err := dm.KillContainerInPod(networkContainer.ID, networkSpec, pod); err != nil {
+			glog.Errorf("Failed to delete container: %v; Skipping pod %q", err, runningPod.ID)
 			errs <- err
 		}
 	}
@@ -1154,75 +1186,152 @@ func (dm *DockerManager) KillPod(pod kubecontainer.Pod) error {
 	return nil
 }
 
-// KillContainerInPod kills a container in the pod.
-func (dm *DockerManager) KillContainerInPod(container api.Container, pod *api.Pod) error {
-	// Locate the container.
-	pods, err := dm.GetPods(false)
-	if err != nil {
-		return err
-	}
-	targetPod := kubecontainer.Pods(pods).FindPod(kubecontainer.GetPodFullName(pod), pod.UID)
-	targetContainer := targetPod.FindContainerByName(container.Name)
-	if targetContainer == nil {
-		return fmt.Errorf("unable to find container %q in pod %q", container.Name, targetPod.Name)
-	}
-	return dm.killContainer(targetContainer.ID)
-}
-
-// TODO(vmarmol): Unexport this as it is no longer used externally.
-// KillContainer kills a container identified by containerID.
-// Internally, it invokes docker's StopContainer API with a timeout of 10s.
-// TODO: Deprecate this function in favor of KillContainerInPod.
-func (dm *DockerManager) KillContainer(containerID types.UID) error {
-	return dm.killContainer(containerID)
-}
-
-func (dm *DockerManager) killContainer(containerID types.UID) error {
-	ID := string(containerID)
-	glog.V(2).Infof("Killing container with id %q", ID)
-	inspect, err := dm.client.InspectContainer(ID)
-	if err != nil {
-		return err
-	}
-	var found bool
-	var preStop string
-	if inspect != nil && inspect.Config != nil && inspect.Config.Labels != nil {
-		preStop, found = inspect.Config.Labels[kubernetesPodLabel]
-	}
-	if found {
-		var pod api.Pod
-		err := latest.Codec.DecodeInto([]byte(preStop), &pod)
+// KillContainerInPod kills a container in the pod. It must be passed either a container ID or a container and pod,
+// and will attempt to lookup the other information if missing.
+func (dm *DockerManager) KillContainerInPod(containerID types.UID, container *api.Container, pod *api.Pod) error {
+	switch {
+	case len(containerID) == 0:
+		// Locate the container.
+		pods, err := dm.GetPods(false)
 		if err != nil {
-			glog.Errorf("Failed to decode prestop: %s, %s", preStop, ID)
-		} else {
-			name := inspect.Config.Labels[kubernetesContainerLabel]
-			var container *api.Container
+			return err
+		}
+		targetPod := kubecontainer.Pods(pods).FindPod(kubecontainer.GetPodFullName(pod), pod.UID)
+		targetContainer := targetPod.FindContainerByName(container.Name)
+		if targetContainer == nil {
+			return fmt.Errorf("unable to find container %q in pod %q", container.Name, targetPod.Name)
+		}
+		containerID = targetContainer.ID
+
+	case container == nil || pod == nil:
+		// Read information about the container from labels
+		inspect, err := dm.client.InspectContainer(string(containerID))
+		if err != nil {
+			return err
+		}
+		storedPod, storedContainer, cerr := containerAndPodFromLabels(inspect)
+		if cerr != nil {
+			glog.Errorf("unable to access pod data from container: %v", err)
+		}
+		if container == nil {
+			container = storedContainer
+		}
+		if pod == nil {
+			pod = storedPod
+		}
+	}
+	return dm.killContainer(containerID, container, pod)
+}
+
+// killContainer accepts a containerID and an optional container or pod containing shutdown policies. Invoke
+// KillContainerInPod if information must be retrieved first.
+func (dm *DockerManager) killContainer(containerID types.UID, container *api.Container, pod *api.Pod) error {
+	ID := string(containerID)
+	name := ID
+	if container != nil {
+		name = fmt.Sprintf("%s %s", name, container.Name)
+	}
+	if pod != nil {
+		name = fmt.Sprintf("%s %s/%s", name, pod.Namespace, pod.Name)
+	}
+
+	gracePeriod := int64(minimumGracePeriodInSeconds)
+	if pod != nil {
+		switch {
+		case pod.DeletionGracePeriodSeconds != nil:
+			gracePeriod = *pod.DeletionGracePeriodSeconds
+		case pod.Spec.TerminationGracePeriodSeconds != nil:
+			gracePeriod = *pod.Spec.TerminationGracePeriodSeconds
+		}
+	}
+	glog.V(2).Infof("Killing container %q with %d second grace period", name, gracePeriod)
+	start := util.Now()
+
+	if pod != nil && container != nil && container.Lifecycle != nil && container.Lifecycle.PreStop != nil {
+		glog.V(4).Infof("Running preStop hook for container %q", name)
+		done := make(chan struct{})
+		go func() {
+			defer close(done)
+			defer util.HandleCrash()
+			if err := dm.runner.Run(ID, pod, container, container.Lifecycle.PreStop); err != nil {
+				glog.Errorf("preStop hook for container %q failed: %v", name, err)
+			}
+		}()
+		select {
+		case <-time.After(time.Duration(gracePeriod) * time.Second):
+			glog.V(2).Infof("preStop hook for container %q did not complete in %d seconds", name, gracePeriod)
+		case <-done:
+			glog.V(4).Infof("preStop hook for container %q completed", name)
+		}
+		gracePeriod -= int64(util.Now().Sub(start.Time).Seconds())
+	}
+
+	dm.readinessManager.RemoveReadiness(ID)
+
+	// always give containers a minimal shutdown window to avoid unnecessary SIGKILLs
+	if gracePeriod < minimumGracePeriodInSeconds {
+		gracePeriod = minimumGracePeriodInSeconds
+	}
+	err := dm.client.StopContainer(ID, uint(gracePeriod))
+	if _, ok := err.(*docker.ContainerNotRunning); ok && err != nil {
+		glog.V(4).Infof("Container %q has already exited", name)
+		return nil
+	}
+	if err == nil {
+		glog.V(2).Infof("Container %q exited after %s", name, util.Now().Sub(start.Time))
+	} else {
+		glog.V(2).Infof("Container %q termination failed after %s: %v", name, util.Now().Sub(start.Time), err)
+	}
+	ref, ok := dm.containerRefManager.GetRef(ID)
+	if !ok {
+		glog.Warningf("No ref for pod '%q'", name)
+	} else {
+		// TODO: pass reason down here, and state, or move this call up the stack.
+		dm.recorder.Eventf(ref, "Killing", "Killing with docker id %v", util.ShortenString(ID, 12))
+	}
+	return err
+}
+
+var errNoPodOnContainer = fmt.Errorf("no pod information labels on Docker container")
+
+// containerAndPodFromLabels tries to load the appropriate container info off of a Docker container's labels
+func containerAndPodFromLabels(inspect *docker.Container) (pod *api.Pod, container *api.Container, err error) {
+	if inspect == nil && inspect.Config == nil && inspect.Config.Labels == nil {
+		return nil, nil, errNoPodOnContainer
+	}
+	labels := inspect.Config.Labels
+
+	// the pod data may not be set
+	if body, found := labels[kubernetesPodLabel]; found {
+		pod = &api.Pod{}
+		if err = latest.Codec.DecodeInto([]byte(body), pod); err == nil {
+			name := labels[kubernetesContainerLabel]
 			for ix := range pod.Spec.Containers {
 				if pod.Spec.Containers[ix].Name == name {
 					container = &pod.Spec.Containers[ix]
 					break
 				}
 			}
-			if container != nil {
-				glog.V(1).Infof("Running preStop hook")
-				if err := dm.runner.Run(ID, &pod, container, container.Lifecycle.PreStop); err != nil {
-					glog.Errorf("failed to run preStop hook: %v", err)
-				}
-			} else {
-				glog.Errorf("unable to find container %v, %s", pod, name)
+			if container == nil {
+				err = fmt.Errorf("unable to find container %s in pod %v", name, pod)
+			}
+		} else {
+			pod = nil
+		}
+	}
+
+	// attempt to find the default grace period if we didn't commit a pod, but set the generic metadata
+	// field (the one used by kill)
+	if pod == nil {
+		if period, ok := labels[kubernetesTerminationGracePeriodLabel]; ok {
+			if seconds, err := strconv.ParseInt(period, 10, 64); err == nil {
+				pod = &api.Pod{}
+				pod.DeletionGracePeriodSeconds = &seconds
 			}
 		}
 	}
-	dm.readinessManager.RemoveReadiness(ID)
-	err = dm.client.StopContainer(ID, 10)
-	ref, ok := dm.containerRefManager.GetRef(ID)
-	if !ok {
-		glog.Warningf("No ref for pod '%v'", ID)
-	} else {
-		// TODO: pass reason down here, and state, or move this call up the stack.
-		dm.recorder.Eventf(ref, "Killing", "Killing with docker id %v", util.ShortenString(ID, 12))
-	}
-	return err
+
+	return
 }
 
 // Run a single container from a pod. Returns the docker container ID
@@ -1259,7 +1368,7 @@ func (dm *DockerManager) runContainerInPod(pod *api.Pod, container *api.Containe
 	if container.Lifecycle != nil && container.Lifecycle.PostStart != nil {
 		handlerErr := dm.runner.Run(id, pod, container, container.Lifecycle.PostStart)
 		if handlerErr != nil {
-			dm.killContainer(types.UID(id))
+			dm.KillContainerInPod(types.UID(id), container, pod)
 			return kubeletTypes.DockerID(""), fmt.Errorf("failed to call event handler: %v", handlerErr)
 		}
 	}
@@ -1540,10 +1649,10 @@ func (dm *DockerManager) SyncPod(pod *api.Pod, runningPod kubecontainer.Pod, pod
 
 	podFullName := kubecontainer.GetPodFullName(pod)
 	containerChanges, err := dm.computePodContainerChanges(pod, runningPod, podStatus)
-	glog.V(3).Infof("Got container changes for pod %q: %+v", podFullName, containerChanges)
 	if err != nil {
 		return err
 	}
+	glog.V(3).Infof("Got container changes for pod %q: %+v", podFullName, containerChanges)
 
 	if containerChanges.StartInfraContainer || (len(containerChanges.ContainersToKeep) == 0 && len(containerChanges.ContainersToStart) == 0) {
 		if len(containerChanges.ContainersToKeep) == 0 && len(containerChanges.ContainersToStart) == 0 {
@@ -1553,7 +1662,7 @@ func (dm *DockerManager) SyncPod(pod *api.Pod, runningPod kubecontainer.Pod, pod
 		}
 
 		// Killing phase: if we want to start new infra container, or nothing is running kill everything (including infra container)
-		err = dm.KillPod(runningPod)
+		err = dm.KillPod(pod, runningPod)
 		if err != nil {
 			return err
 		}
@@ -1563,7 +1672,15 @@ func (dm *DockerManager) SyncPod(pod *api.Pod, runningPod kubecontainer.Pod, pod
 			_, keep := containerChanges.ContainersToKeep[kubeletTypes.DockerID(container.ID)]
 			if !keep {
 				glog.V(3).Infof("Killing unwanted container %+v", container)
-				err = dm.KillContainer(container.ID)
+				// attempt to find the appropriate container policy
+				var podContainer *api.Container
+				for i, c := range pod.Spec.Containers {
+					if c.Name == container.Name {
+						podContainer = &pod.Spec.Containers[i]
+						break
+					}
+				}
+				err = dm.KillContainerInPod(container.ID, podContainer, pod)
 				if err != nil {
 					glog.Errorf("Error killing container: %v", err)
 				}

pkg/kubelet/dockertools/manager_test.go

@@ -405,7 +405,7 @@ func TestKillContainerInPod(t *testing.T) {
 		manager.readinessManager.SetReadiness(c.ID, true)
 	}
 
-	if err := manager.KillContainerInPod(pod.Spec.Containers[0], pod); err != nil {
+	if err := manager.KillContainerInPod("", &pod.Spec.Containers[0], pod); err != nil {
 		t.Errorf("unexpected error: %v", err)
 	}
 	// Assert the container has been stopped.
@@ -478,14 +478,14 @@ func TestKillContainerInPodWithPreStop(t *testing.T) {
 		manager.readinessManager.SetReadiness(c.ID, true)
 	}
 
-	if err := manager.KillContainerInPod(pod.Spec.Containers[0], pod); err != nil {
+	if err := manager.KillContainerInPod("", &pod.Spec.Containers[0], pod); err != nil {
 		t.Errorf("unexpected error: %v", err)
 	}
 	// Assert the container has been stopped.
 	if err := fakeDocker.AssertStopped([]string{containerToKill.ID}); err != nil {
 		t.Errorf("container was not stopped correctly: %v", err)
 	}
-	verifyCalls(t, fakeDocker, []string{"list", "inspect_container", "create_exec", "start_exec", "stop"})
+	verifyCalls(t, fakeDocker, []string{"list", "create_exec", "start_exec", "stop"})
 	if !reflect.DeepEqual(expectedCmd, fakeDocker.execCmd) {
 		t.Errorf("expected: %v, got %v", expectedCmd, fakeDocker.execCmd)
 	}
@@ -522,7 +522,7 @@ func TestKillContainerInPodWithError(t *testing.T) {
 		manager.readinessManager.SetReadiness(c.ID, true)
 	}
 
-	if err := manager.KillContainerInPod(pod.Spec.Containers[0], pod); err == nil {
+	if err := manager.KillContainerInPod("", &pod.Spec.Containers[0], pod); err == nil {
 		t.Errorf("expected error, found nil")
 	}
 
@@ -1021,7 +1021,7 @@ func TestSyncPodDeletesWithNoPodInfraContainer(t *testing.T) {
 
 	verifyCalls(t, fakeDocker, []string{
 		// Kill the container since pod infra container is not running.
-		"inspect_container", "stop",
+		"stop",
 		// Create pod infra container.
 		"create", "start", "inspect_container",
 		// Create container.
@@ -1096,7 +1096,7 @@ func TestSyncPodDeletesDuplicate(t *testing.T) {
 		// Check the pod infra container.
 		"inspect_container",
 		// Kill the duplicated container.
-		"inspect_container", "stop",
+		"stop",
 	})
 	// Expect one of the duplicates to be killed.
 	if len(fakeDocker.Stopped) != 1 || (fakeDocker.Stopped[0] != "1234" && fakeDocker.Stopped[0] != "4567") {
@@ -1150,7 +1150,7 @@ func TestSyncPodBadHash(t *testing.T) {
 		// Check the pod infra container.
 		"inspect_container",
 		// Kill and restart the bad hash container.
-		"inspect_container", "stop", "create", "start", "inspect_container",
+		"stop", "create", "start", "inspect_container",
 	})
 
 	if err := fakeDocker.AssertStopped([]string{"1234"}); err != nil {
@@ -1208,7 +1208,7 @@ func TestSyncPodsUnhealthy(t *testing.T) {
 		// Check the pod infra container.
 		"inspect_container",
 		// Kill the unhealthy container.
-		"inspect_container", "stop",
+		"stop",
 		// Restart the unhealthy container.
 		"create", "start", "inspect_container",
 	})
@@ -1441,9 +1441,9 @@ func TestSyncPodWithRestartPolicy(t *testing.T) {
 			api.RestartPolicyNever,
 			[]string{
 				// Check the pod infra container.
-				"inspect_container",
+				"inspect_container", "inspect_container",
 				// Stop the last pod infra container.
-				"inspect_container", "stop",
+				"stop",
 			},
 			[]string{},
 			[]string{"9876"},
@@ -1910,7 +1910,7 @@ func TestSyncPodEventHandlerFails(t *testing.T) {
 		// Create the container.
 		"create", "start",
 		// Kill the container since event handler fails.
-		"inspect_container", "stop",
+		"stop",
 	})
 
 	// TODO(yifan): Check the stopped container's name.

pkg/kubelet/kubelet.go

@@ -1124,8 +1124,8 @@ func parseResolvConf(reader io.Reader) (nameservers []string, searches []string,
 }
 
 // Kill all running containers in a pod (includes the pod infra container).
-func (kl *Kubelet) killPod(pod kubecontainer.Pod) error {
-	return kl.containerRuntime.KillPod(pod)
+func (kl *Kubelet) killPod(pod *api.Pod, runningPod kubecontainer.Pod) error {
+	return kl.containerRuntime.KillPod(pod, runningPod)
 }
 
 type empty struct{}
@@ -1181,9 +1181,10 @@ func (kl *Kubelet) syncPod(pod *api.Pod, mirrorPod *api.Pod, runningPod kubecont
 	}()
 
 	// Kill pods we can't run.
-	err := canRunPod(pod)
-	if err != nil {
-		kl.killPod(runningPod)
+	if err := canRunPod(pod); err != nil || pod.DeletionTimestamp != nil {
+		if err := kl.killPod(pod, runningPod); err != nil {
+			util.HandleError(err)
+		}
 		return err
 	}
 
@@ -1370,6 +1371,32 @@ func (kl *Kubelet) cleanupOrphanedVolumes(pods []*api.Pod, runningPods []*kubeco
 	return nil
 }
 
+// Delete any pods that are no longer running and are marked for deletion.
+func (kl *Kubelet) cleanupTerminatedPods(pods []*api.Pod, runningPods []*kubecontainer.Pod) error {
+	var terminating []*api.Pod
+	for _, pod := range pods {
+		if pod.DeletionTimestamp != nil {
+			found := false
+			for _, runningPod := range runningPods {
+				if runningPod.ID == pod.UID {
+					found = true
+					break
+				}
+			}
+			if found {
+				podFullName := kubecontainer.GetPodFullName(pod)
+				glog.V(5).Infof("Keeping terminated pod %q and uid %q, still running", podFullName, pod.UID)
+				continue
+			}
+			terminating = append(terminating, pod)
+		}
+	}
+	if !kl.statusManager.TerminatePods(terminating) {
+		return errors.New("not all pods were successfully terminated")
+	}
+	return nil
+}
+
 // pastActiveDeadline returns true if the pod has been active for more than
 // ActiveDeadlineSeconds.
 func (kl *Kubelet) pastActiveDeadline(pod *api.Pod) bool {
@@ -1532,6 +1559,10 @@ func (kl *Kubelet) cleanupPods(allPods []*api.Pod, admittedPods []*api.Pod) erro
 	// Remove any orphaned mirror pods.
 	kl.podManager.DeleteOrphanedMirrorPods()
 
+	if err := kl.cleanupTerminatedPods(allPods, runningPods); err != nil {
+		glog.Errorf("Failed to cleanup terminated pods: %v", err)
+	}
+
 	return err
 }
 
@@ -1554,7 +1585,7 @@ func (kl *Kubelet) killUnwantedPods(desiredPods map[types.UID]empty,
 			}()
 			glog.V(1).Infof("Killing unwanted pod %q", pod.Name)
 			// Stop the containers.
-			err = kl.killPod(*pod)
+			err = kl.killPod(nil, *pod)
 			if err != nil {
 				glog.Errorf("Failed killing the pod %q: %v", pod.Name, err)
 				return

pkg/kubelet/mirror_client.go

@@ -64,7 +64,7 @@ func (mc *basicMirrorClient) DeleteMirrorPod(podFullName string) error {
 		return err
 	}
 	glog.V(4).Infof("Deleting a mirror pod %q", podFullName)
-	if err := mc.apiserverClient.Pods(namespace).Delete(name, nil); err != nil {
+	if err := mc.apiserverClient.Pods(namespace).Delete(name, api.NewDeleteOptions(0)); err != nil {
 		glog.Errorf("Failed deleting a mirror pod %q: %v", podFullName, err)
 	}
 	return nil

pkg/kubelet/rkt/rkt.go

@@ -693,11 +693,11 @@ func (r *runtime) GetPods(all bool) ([]*kubecontainer.Pod, error) {
 }
 
 // KillPod invokes 'systemctl kill' to kill the unit that runs the pod.
-func (r *runtime) KillPod(pod kubecontainer.Pod) error {
-	glog.V(4).Infof("Rkt is killing pod: name %q.", pod.Name)
+func (r *runtime) KillPod(pod *api.Pod, runningPod kubecontainer.Pod) error {
+	glog.V(4).Infof("Rkt is killing pod: name %q.", runningPod.Name)
 
 	// TODO(yifan): More graceful stop. Replace with StopUnit and wait for a timeout.
-	r.systemd.KillUnit(makePodServiceFileName(pod.ID), int32(syscall.SIGKILL))
+	r.systemd.KillUnit(makePodServiceFileName(runningPod.ID), int32(syscall.SIGKILL))
 	return r.systemd.Reload()
 }
 
@@ -966,7 +966,7 @@ func (r *runtime) SyncPod(pod *api.Pod, runningPod kubecontainer.Pod, podStatus
 
 	if restartPod {
 		// TODO(yifan): Handle network plugin.
-		if err := r.KillPod(runningPod); err != nil {
+		if err := r.KillPod(pod, runningPod); err != nil {
 			return err
 		}
 		if err := r.RunPod(pod, pullSecrets); err != nil {

pkg/kubelet/status_manager.go

@@ -24,6 +24,7 @@ import (
 
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/errors"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	kubeletTypes "k8s.io/kubernetes/pkg/kubelet/types"
@@ -122,7 +123,7 @@ func (s *statusManager) SetPodStatus(pod *api.Pod, status api.PodStatus) {
 	// Currently this routine is not called for the same pod from multiple
 	// workers and/or the kubelet but dropping the lock before sending the
 	// status down the channel feels like an easy way to get a bullet in foot.
-	if !found || !isStatusEqual(&oldStatus, &status) {
+	if !found || !isStatusEqual(&oldStatus, &status) || pod.DeletionTimestamp != nil {
 		s.podStatuses[podFullName] = status
 		s.podStatusChannel <- podStatusSyncRequest{pod, status}
 	} else {
@@ -130,6 +131,29 @@ func (s *statusManager) SetPodStatus(pod *api.Pod, status api.PodStatus) {
 	}
 }
 
+// TerminatePods resets the container status for the provided pods to terminated and triggers
+// a status update. This function may not enqueue all the provided pods, in which case it will
+// return false
+func (s *statusManager) TerminatePods(pods []*api.Pod) bool {
+	sent := true
+	s.podStatusesLock.Lock()
+	defer s.podStatusesLock.Unlock()
+	for _, pod := range pods {
+		for i := range pod.Status.ContainerStatuses {
+			pod.Status.ContainerStatuses[i].State = api.ContainerState{
+				Terminated: &api.ContainerStateTerminated{},
+			}
+		}
+		select {
+		case s.podStatusChannel <- podStatusSyncRequest{pod, pod.Status}:
+		default:
+			sent = false
+			glog.V(4).Infof("Termination notice for %q was dropped because the status channel is full", kubeletUtil.FormatPodName(pod))
+		}
+	}
+	return sent
+}
+
 func (s *statusManager) DeletePodStatus(podFullName string) {
 	s.podStatusesLock.Lock()
 	defer s.podStatusesLock.Unlock()
@@ -161,13 +185,33 @@ func (s *statusManager) syncBatch() error {
 	}
 	// TODO: make me easier to express from client code
 	statusPod, err = s.kubeClient.Pods(statusPod.Namespace).Get(statusPod.Name)
+	if errors.IsNotFound(err) {
+		glog.V(3).Infof("Pod %q was deleted on the server", pod.Name)
+		return nil
+	}
 	if err == nil {
+		if len(pod.UID) > 0 && statusPod.UID != pod.UID {
+			glog.V(3).Infof("Pod %q was deleted and then recreated, skipping status update", kubeletUtil.FormatPodName(pod))
+			return nil
+		}
 		statusPod.Status = status
-		_, err = s.kubeClient.Pods(pod.Namespace).UpdateStatus(statusPod)
 		// TODO: handle conflict as a retry, make that easier too.
+		statusPod, err = s.kubeClient.Pods(pod.Namespace).UpdateStatus(statusPod)
 		if err == nil {
 			glog.V(3).Infof("Status for pod %q updated successfully", kubeletUtil.FormatPodName(pod))
-			return nil
+
+			if pod.DeletionTimestamp == nil {
+				return nil
+			}
+			if !notRunning(pod.Status.ContainerStatuses) {
+				glog.V(3).Infof("Pod %q is terminated, but some pods are still running", pod.Name)
+				return nil
+			}
+			if err := s.kubeClient.Pods(statusPod.Namespace).Delete(statusPod.Name, api.NewDeleteOptions(0)); err == nil {
+				glog.V(3).Infof("Pod %q fully terminated and removed from etcd", statusPod.Name)
+				s.DeletePodStatus(podFullName)
+				return nil
+			}
 		}
 	}
 
@@ -181,3 +225,14 @@ func (s *statusManager) syncBatch() error {
 	go s.DeletePodStatus(podFullName)
 	return fmt.Errorf("error updating status for pod %q: %v", kubeletUtil.FormatPodName(pod), err)
 }
+
+// notRunning returns true if every status is terminated or waiting, or the status list
+// is empty.
+func notRunning(statuses []api.ContainerStatus) bool {
+	for _, status := range statuses {
+		if status.State.Terminated == nil && status.State.Waiting == nil {
+			return false
+		}
+	}
+	return true
+}

pkg/kubelet/status_manager_test.go

@@ -153,8 +153,21 @@ func TestUnchangedStatus(t *testing.T) {
 	verifyUpdates(t, syncer, 1)
 }
 
+func TestSyncBatchIgnoresNotFound(t *testing.T) {
+	syncer := newTestStatusManager()
+	syncer.SetPodStatus(testPod, getRandomPodStatus())
+	err := syncer.syncBatch()
+	if err != nil {
+		t.Errorf("unexpected syncing error: %v", err)
+	}
+	verifyActions(t, syncer.kubeClient, []testclient.Action{
+		testclient.GetActionImpl{ActionImpl: testclient.ActionImpl{Verb: "get", Resource: "pods"}},
+	})
+}
+
 func TestSyncBatch(t *testing.T) {
 	syncer := newTestStatusManager()
+	syncer.kubeClient = testclient.NewSimpleFake(testPod)
 	syncer.SetPodStatus(testPod, getRandomPodStatus())
 	err := syncer.syncBatch()
 	if err != nil {
@@ -167,6 +180,22 @@ func TestSyncBatch(t *testing.T) {
 	)
 }
 
+func TestSyncBatchChecksMismatchedUID(t *testing.T) {
+	syncer := newTestStatusManager()
+	testPod.UID = "first"
+	differentPod := *testPod
+	differentPod.UID = "second"
+	syncer.kubeClient = testclient.NewSimpleFake(testPod)
+	syncer.SetPodStatus(&differentPod, getRandomPodStatus())
+	err := syncer.syncBatch()
+	if err != nil {
+		t.Errorf("unexpected syncing error: %v", err)
+	}
+	verifyActions(t, syncer.kubeClient, []testclient.Action{
+		testclient.GetActionImpl{ActionImpl: testclient.ActionImpl{Verb: "get", Resource: "pods"}},
+	})
+}
+
 // shuffle returns a new shuffled list of container statuses.
 func shuffle(statuses []api.ContainerStatus) []api.ContainerStatus {
 	numStatuses := len(statuses)