Volume manager verify containers terminated before deleting

pkg/kubelet/kubelet.go

@@ -504,7 +504,8 @@ func NewMainKubelet(
 		hostname,
 		klet.podManager,
 		klet.kubeClient,
-		klet.volumePluginMgr)
+		klet.volumePluginMgr,
+		klet.containerRuntime)
 
 	runtimeCache, err := kubecontainer.NewRuntimeCache(klet.containerRuntime)
 	if err != nil {

pkg/kubelet/kubelet_test.go

@@ -299,7 +299,8 @@ func newTestKubeletWithImageList(
 		kubelet.hostname,
 		kubelet.podManager,
 		fakeKubeClient,
-		kubelet.volumePluginMgr)
+		kubelet.volumePluginMgr,
+		fakeRuntime)
 	if err != nil {
 		t.Fatalf("failed to initialize volume manager: %v", err)
 	}

pkg/kubelet/runonce_test.go

@@ -97,7 +97,8 @@ func TestRunOnce(t *testing.T) {
 		kb.hostname,
 		kb.podManager,
 		kb.kubeClient,
-		kb.volumePluginMgr)
+		kb.volumePluginMgr,
+		fakeRuntime)
 
 	kb.networkPlugin, _ = network.InitNetworkPlugin([]network.NetworkPlugin{}, "", nettest.NewFakeHost(nil), componentconfig.HairpinNone, kb.nonMasqueradeCIDR)
 	// TODO: Factor out "StatsProvider" from Kubelet so we don't have a cyclic dependency

pkg/kubelet/volume/populator/desired_state_of_world_populator.go

@@ -29,7 +29,9 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
+	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	"k8s.io/kubernetes/pkg/kubelet/pod"
+	"k8s.io/kubernetes/pkg/kubelet/util/format"
 	"k8s.io/kubernetes/pkg/kubelet/volume/cache"
 	"k8s.io/kubernetes/pkg/types"
 	"k8s.io/kubernetes/pkg/util/wait"
@@ -64,24 +66,31 @@ type DesiredStateOfWorldPopulator interface {
 func NewDesiredStateOfWorldPopulator(
 	kubeClient internalclientset.Interface,
 	loopSleepDuration time.Duration,
+	getPodStatusRetryDuration time.Duration,
 	podManager pod.Manager,
-	desiredStateOfWorld cache.DesiredStateOfWorld) DesiredStateOfWorldPopulator {
+	desiredStateOfWorld cache.DesiredStateOfWorld,
+	kubeContainerRuntime kubecontainer.Runtime) DesiredStateOfWorldPopulator {
 	return &desiredStateOfWorldPopulator{
-		kubeClient:          kubeClient,
-		loopSleepDuration:   loopSleepDuration,
-		podManager:          podManager,
-		desiredStateOfWorld: desiredStateOfWorld,
+		kubeClient:                kubeClient,
+		loopSleepDuration:         loopSleepDuration,
+		getPodStatusRetryDuration: getPodStatusRetryDuration,
+		podManager:                podManager,
+		desiredStateOfWorld:       desiredStateOfWorld,
 		pods: processedPods{
 			processedPods: make(map[volumetypes.UniquePodName]bool)},
+		kubeContainerRuntime: kubeContainerRuntime,
 	}
 }
 
 type desiredStateOfWorldPopulator struct {
-	kubeClient          internalclientset.Interface
-	loopSleepDuration   time.Duration
-	podManager          pod.Manager
-	desiredStateOfWorld cache.DesiredStateOfWorld
-	pods                processedPods
+	kubeClient                internalclientset.Interface
+	loopSleepDuration         time.Duration
+	getPodStatusRetryDuration time.Duration
+	podManager                pod.Manager
+	desiredStateOfWorld       cache.DesiredStateOfWorld
+	pods                      processedPods
+	kubeContainerRuntime      kubecontainer.Runtime
+	timeOfLastGetPodStatus    time.Time
 }
 
 type processedPods struct {
@@ -102,6 +111,20 @@ func (dswp *desiredStateOfWorldPopulator) populatorLoopFunc() func() {
 	return func() {
 		dswp.findAndAddNewPods()
 
+		// findAndRemoveDeletedPods() calls out to the container runtime to
+		// determine if the containers for a given pod are terminated. This is
+		// an expensive operation, therefore we limit the rate that
+		// findAndRemoveDeletedPods() is called independently of the main
+		// populator loop.
+		if time.Since(dswp.timeOfLastGetPodStatus) < dswp.getPodStatusRetryDuration {
+			glog.V(5).Infof(
+				"Skipping findAndRemoveDeletedPods(). Not permitted until %v (getPodStatusRetryDuration %v).",
+				dswp.timeOfLastGetPodStatus.Add(dswp.getPodStatusRetryDuration),
+				dswp.getPodStatusRetryDuration)
+
+			return
+		}
+
 		dswp.findAndRemoveDeletedPods()
 	}
 }
@@ -117,19 +140,60 @@ func (dswp *desiredStateOfWorldPopulator) findAndAddNewPods() {
 // Iterate through all pods in desired state of world, and remove if they no
 // longer exist
 func (dswp *desiredStateOfWorldPopulator) findAndRemoveDeletedPods() {
+	var runningPods []*kubecontainer.Pod
+
+	runningPodsFetched := false
 	for _, volumeToMount := range dswp.desiredStateOfWorld.GetVolumesToMount() {
 		if _, podExists :=
-			dswp.podManager.GetPodByUID(volumeToMount.Pod.UID); !podExists {
-			glog.V(10).Infof(
-				"Removing volume %q (volSpec=%q) for pod %q from desired state.",
-				volumeToMount.VolumeName,
-				volumeToMount.VolumeSpec.Name(),
-				volumeToMount.PodName)
-
-			dswp.desiredStateOfWorld.DeletePodFromVolume(
-				volumeToMount.PodName, volumeToMount.VolumeName)
-			dswp.deleteProcessedPod(volumeToMount.PodName)
+			dswp.podManager.GetPodByUID(volumeToMount.Pod.UID); podExists {
+			continue
 		}
+
+		// Once a pod has been deleted from kubelet pod manager, do not delete
+		// it immediately from volume manager. Instead, check the kubelet
+		// containerRuntime to verify that all containers in the pod have been
+		// terminated.
+		if !runningPodsFetched {
+			var getPodsErr error
+			runningPods, getPodsErr = dswp.kubeContainerRuntime.GetPods(false)
+			if getPodsErr != nil {
+				glog.Errorf(
+					"kubeContainerRuntime.findAndRemoveDeletedPods returned error %v.",
+					getPodsErr)
+				continue
+			}
+
+			runningPodsFetched = true
+			dswp.timeOfLastGetPodStatus = time.Now()
+		}
+
+		runningContainers := false
+		for _, runningPod := range runningPods {
+			if runningPod.ID == volumeToMount.Pod.UID {
+				if len(runningPod.Containers) > 0 {
+					runningContainers = true
+				}
+
+				break
+			}
+		}
+
+		if runningContainers {
+			glog.V(5).Infof(
+				"Pod %q has been removed from pod manager. However, it still has one or more containers in the non-exited state. Therefore it will not be removed from volume manager.",
+				format.Pod(volumeToMount.Pod))
+			continue
+		}
+
+		glog.V(5).Infof(
+			"Removing volume %q (volSpec=%q) for pod %q from desired state.",
+			volumeToMount.VolumeName,
+			volumeToMount.VolumeSpec.Name(),
+			format.Pod(volumeToMount.Pod))
+
+		dswp.desiredStateOfWorld.DeletePodFromVolume(
+			volumeToMount.PodName, volumeToMount.VolumeName)
+		dswp.deleteProcessedPod(volumeToMount.PodName)
 	}
 }
 
@@ -151,10 +215,9 @@ func (dswp *desiredStateOfWorldPopulator) processPodVolumes(pod *api.Pod) {
 			dswp.createVolumeSpec(podVolume, pod.Namespace)
 		if err != nil {
 			glog.Errorf(
-				"Error processing volume %q for pod %q/%q: %v",
+				"Error processing volume %q for pod %q: %v",
 				podVolume.Name,
-				pod.Namespace,
-				pod.Name,
+				format.Pod(pod),
 				err)
 			continue
 		}

pkg/kubelet/volume/volume_manager.go

@@ -25,6 +25,7 @@ import (
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
 	"k8s.io/kubernetes/pkg/kubelet/container"
+	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	"k8s.io/kubernetes/pkg/kubelet/pod"
 	"k8s.io/kubernetes/pkg/kubelet/util/format"
 	"k8s.io/kubernetes/pkg/kubelet/volume/cache"
@@ -48,6 +49,12 @@ const (
 	// DesiredStateOfWorldPopulator loop waits between successive executions
 	desiredStateOfWorldPopulatorLoopSleepPeriod time.Duration = 100 * time.Millisecond
 
+	// desiredStateOfWorldPopulatorGetPodStatusRetryDuration is the amount of
+	// time the DesiredStateOfWorldPopulator loop waits between successive pod
+	// cleanup calls (to prevent calling containerruntime.GetPodStatus too
+	// frequently).
+	desiredStateOfWorldPopulatorGetPodStatusRetryDuration time.Duration = 2 * time.Second
+
 	// podAttachAndMountTimeout is the maximum amount of time the
 	// WaitForAttachAndMount call will wait for all volumes in the specified pod
 	// to be attached and mounted. Even though cloud operations can take several
@@ -120,7 +127,8 @@ func NewVolumeManager(
 	hostName string,
 	podManager pod.Manager,
 	kubeClient internalclientset.Interface,
-	volumePluginMgr *volume.VolumePluginMgr) (VolumeManager, error) {
+	volumePluginMgr *volume.VolumePluginMgr,
+	kubeContainerRuntime kubecontainer.Runtime) (VolumeManager, error) {
 	vm := &volumeManager{
 		kubeClient:          kubeClient,
 		volumePluginMgr:     volumePluginMgr,
@@ -143,8 +151,10 @@ func NewVolumeManager(
 	vm.desiredStateOfWorldPopulator = populator.NewDesiredStateOfWorldPopulator(
 		kubeClient,
 		desiredStateOfWorldPopulatorLoopSleepPeriod,
+		desiredStateOfWorldPopulatorGetPodStatusRetryDuration,
 		podManager,
-		vm.desiredStateOfWorld)
+		vm.desiredStateOfWorld,
+		kubeContainerRuntime)
 
 	return vm, nil
 }