test: Add node e2e test to verify static pod termination

Add node e2e test to verify that static pods can be started after a
previous static pod with the same config temporarily failed termination.

The scenario is:

1. Static pod is started
2. Static pod is deleted
3. Static pod termination fails (internally `syncTerminatedPod` fails)
4. At later time, pod termination should succeed
5. New static pod with the same config is (re)-added
6. New static pod is expected to start successfully

To repro this scenario, setup a pod using a NFS mount. The NFS server is
stopped which will result in volumes failing to unmount and
`syncTerminatedPod` to fail. The NFS server is later started, allowing
the volume to unmount successfully.

xref:

1. https://github.com/kubernetes/kubernetes/pull/113145#issuecomment-1289587988
2. https://github.com/kubernetes/kubernetes/pull/113065
3. https://github.com/kubernetes/kubernetes/pull/113093

Signed-off-by: David Porter <david@porter.me>

test/e2e/framework/pod/output/output.go

@@ -121,6 +121,15 @@ func LookForStringInLog(ns, podName, container, expectedString string, timeout t
 	})
 }
 
+// LookForStringInLogWithoutKubectl looks for the given string in the log of a specific pod container
+func LookForStringInLogWithoutKubectl(ctx context.Context, client clientset.Interface, ns string, podName string, container string, expectedString string, timeout time.Duration) (result string, err error) {
+	return lookForString(expectedString, timeout, func() string {
+		podLogs, err := e2epod.GetPodLogs(ctx, client, ns, podName, container)
+		framework.ExpectNoError(err)
+		return podLogs
+	})
+}
+
 // CreateEmptyFileOnPod creates empty file at given path on the pod.
 func CreateEmptyFileOnPod(namespace string, podName string, filePath string) error {
 	_, err := e2ekubectl.RunKubectl(namespace, "exec", podName, "--", "/bin/sh", "-c", fmt.Sprintf("touch %s", filePath))

test/e2e/framework/volume/fixtures.go

@@ -149,6 +149,10 @@ type Test struct {
 
 // NewNFSServer is a NFS-specific wrapper for CreateStorageServer.
 func NewNFSServer(ctx context.Context, cs clientset.Interface, namespace string, args []string) (config TestConfig, pod *v1.Pod, host string) {
+	return NewNFSServerWithNodeName(ctx, cs, namespace, args, "")
+}
+
+func NewNFSServerWithNodeName(ctx context.Context, cs clientset.Interface, namespace string, args []string, nodeName string) (config TestConfig, pod *v1.Pod, host string) {
 	config = TestConfig{
 		Namespace:          namespace,
 		Prefix:             "nfs",
@@ -157,6 +161,10 @@ func NewNFSServer(ctx context.Context, cs clientset.Interface, namespace string,
 		ServerVolumes:      map[string]string{"": "/exports"},
 		ServerReadyMessage: "NFS started",
 	}
+	if nodeName != "" {
+		config.ClientNodeSelection = e2epod.NodeSelection{Name: nodeName}
+	}
+
 	if len(args) > 0 {
 		config.ServerArgs = args
 	}
@@ -329,6 +337,10 @@ func startVolumeServer(ctx context.Context, client clientset.Interface, config T
 		},
 	}
 
+	if config.ClientNodeSelection.Name != "" {
+		serverPod.Spec.NodeName = config.ClientNodeSelection.Name
+	}
+
 	var pod *v1.Pod
 	serverPod, err := podClient.Create(ctx, serverPod, metav1.CreateOptions{})
 	// ok if the server pod already exists. TODO: make this controllable by callers
@@ -355,7 +367,7 @@ func startVolumeServer(ctx context.Context, client clientset.Interface, config T
 		}
 	}
 	if config.ServerReadyMessage != "" {
-		_, err := e2epodoutput.LookForStringInLog(pod.Namespace, pod.Name, serverPodName, config.ServerReadyMessage, VolumeServerPodStartupTimeout)
+		_, err := e2epodoutput.LookForStringInLogWithoutKubectl(ctx, client, pod.Namespace, pod.Name, serverPodName, config.ServerReadyMessage, VolumeServerPodStartupTimeout)
 		framework.ExpectNoError(err, "Failed to find %q in pod logs: %s", config.ServerReadyMessage, err)
 	}
 	return pod

test/e2e_node/mirror_pod_test.go

@@ -40,11 +40,13 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"github.com/onsi/ginkgo/v2"
 	"github.com/onsi/gomega"
+	"k8s.io/cli-runtime/pkg/printers"
+	e2evolume "k8s.io/kubernetes/test/e2e/framework/volume"
 )
 
 var _ = SIGDescribe("MirrorPod", func() {
 	f := framework.NewDefaultFramework("mirror-pod")
-	f.NamespacePodSecurityEnforceLevel = admissionapi.LevelBaseline
+	f.NamespacePodSecurityEnforceLevel = admissionapi.LevelPrivileged
 	ginkgo.Context("when create a mirror pod ", func() {
 		var ns, podPath, staticPodName, mirrorPodName string
 		ginkgo.BeforeEach(func(ctx context.Context) {
@@ -196,8 +198,179 @@ var _ = SIGDescribe("MirrorPod", func() {
 			}, 2*time.Minute, time.Second*4).Should(gomega.BeNil())
 		})
 	})
+	ginkgo.Context("when recreating a static pod", func() {
+		var ns, podPath, staticPodName, mirrorPodName string
+		ginkgo.It("it should launch successfully even if it temporarily failed termination due to volume failing to unmount [NodeConformance] [Serial]", func(ctx context.Context) {
+			node := getNodeName(ctx, f)
+			ns = f.Namespace.Name
+			c := f.ClientSet
+			nfsTestConfig, nfsServerPod, nfsServerHost := e2evolume.NewNFSServerWithNodeName(ctx, c, ns, []string{"-G", "777", "/exports"}, node)
+			ginkgo.DeferCleanup(func(ctx context.Context) {
+				framework.Logf("Cleaning up NFS server pod")
+				e2evolume.TestServerCleanup(ctx, f, nfsTestConfig)
+			})
+
+			podPath = framework.TestContext.KubeletConfig.StaticPodPath
+			staticPodName = "static-pod-nfs-test-pod" + string(uuid.NewUUID())
+			mirrorPodName = staticPodName + "-" + framework.TestContext.NodeName
+
+			ginkgo.By(fmt.Sprintf("Creating nfs test pod: %s", staticPodName))
+
+			err := createStaticPodUsingNfs(nfsServerHost, node, "sleep 999999", podPath, staticPodName, ns)
+			framework.ExpectNoError(err)
+			ginkgo.By(fmt.Sprintf("Wating for nfs test pod: %s to start running...", staticPodName))
+			gomega.Eventually(func() error {
+				return checkMirrorPodRunning(ctx, f.ClientSet, mirrorPodName, ns)
+			}, 2*time.Minute, time.Second*4).Should(gomega.BeNil())
+
+			mirrorPod, err := c.CoreV1().Pods(ns).Get(ctx, mirrorPodName, metav1.GetOptions{})
+			framework.ExpectNoError(err)
+
+			hash, ok := mirrorPod.Annotations[kubetypes.ConfigHashAnnotationKey]
+			if !ok || hash == "" {
+				framework.Failf("Failed to get hash for mirrorPod")
+			}
+
+			ginkgo.By("Stopping the NFS server")
+			stopNfsServer(f, nfsServerPod)
+
+			ginkgo.By("Waiting for NFS server to stop...")
+			time.Sleep(30 * time.Second)
+
+			ginkgo.By(fmt.Sprintf("Deleting the static nfs test pod: %s", staticPodName))
+			err = deleteStaticPod(podPath, staticPodName, ns)
+			framework.ExpectNoError(err)
+
+			// Wait 5 mins for syncTerminatedPod to fail. We expect that the pod volume should not be cleaned up because the NFS server is down.
+			gomega.Consistently(func() bool {
+				return podVolumeDirectoryExists(types.UID(hash))
+			}, 5*time.Minute, 10*time.Second).Should(gomega.BeTrue(), "pod volume should exist while nfs server is stopped")
+
+			ginkgo.By("Start the NFS server")
+			restartNfsServer(f, nfsServerPod)
+
+			ginkgo.By("Waiting for the pod volume to deleted after the NFS server is started")
+			gomega.Eventually(func() bool {
+				return podVolumeDirectoryExists(types.UID(hash))
+			}, 5*time.Minute, 10*time.Second).Should(gomega.BeFalse(), "pod volume should be deleted after nfs server is started")
+
+			// Create the static pod again with the same config and expect it to start running
+			err = createStaticPodUsingNfs(nfsServerHost, node, "sleep 999999", podPath, staticPodName, ns)
+			framework.ExpectNoError(err)
+			ginkgo.By(fmt.Sprintf("Wating for nfs test pod: %s to start running (after being recreated)", staticPodName))
+			gomega.Eventually(func() error {
+				return checkMirrorPodRunning(ctx, f.ClientSet, mirrorPodName, ns)
+			}, 5*time.Minute, 5*time.Second).Should(gomega.BeNil())
+		})
+
+		ginkgo.AfterEach(func(ctx context.Context) {
+			ginkgo.By("delete the static pod")
+			err := deleteStaticPod(podPath, staticPodName, ns)
+			framework.ExpectNoError(err)
+
+			ginkgo.By("wait for the mirror pod to disappear")
+			gomega.Eventually(ctx, func(ctx context.Context) error {
+				return checkMirrorPodDisappear(ctx, f.ClientSet, mirrorPodName, ns)
+			}, 2*time.Minute, time.Second*4).Should(gomega.BeNil())
+
+		})
+
+	})
+
 })
 
+func podVolumeDirectoryExists(uid types.UID) bool {
+	podVolumePath := fmt.Sprintf("/var/lib/kubelet/pods/%s/volumes/", uid)
+	var podVolumeDirectoryExists bool
+
+	if _, err := os.Stat(podVolumePath); !os.IsNotExist(err) {
+		podVolumeDirectoryExists = true
+	}
+
+	return podVolumeDirectoryExists
+}
+
+// Restart the passed-in nfs-server by issuing a `/usr/sbin/rpc.nfsd 1` command in the
+// pod's (only) container. This command changes the number of nfs server threads from
+// (presumably) zero back to 1, and therefore allows nfs to open connections again.
+func restartNfsServer(f *framework.Framework, serverPod *v1.Pod) {
+	const startcmd = "/usr/sbin/rpc.nfsd 1"
+	_, _, err := e2evolume.PodExec(f, serverPod, startcmd)
+	framework.ExpectNoError(err)
+
+}
+
+// Stop the passed-in nfs-server by issuing a `/usr/sbin/rpc.nfsd 0` command in the
+// pod's (only) container. This command changes the number of nfs server threads to 0,
+// thus closing all open nfs connections.
+func stopNfsServer(f *framework.Framework, serverPod *v1.Pod) {
+	const stopcmd = "/usr/sbin/rpc.nfsd 0"
+	_, _, err := e2evolume.PodExec(f, serverPod, stopcmd)
+	framework.ExpectNoError(err)
+}
+
+func createStaticPodUsingNfs(nfsIP string, nodeName string, cmd string, dir string, name string, ns string) error {
+	ginkgo.By("create pod using nfs volume")
+
+	isPrivileged := true
+	cmdLine := []string{"-c", cmd}
+	pod := &v1.Pod{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Pod",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      name,
+			Namespace: ns,
+		},
+		Spec: v1.PodSpec{
+			NodeName: nodeName,
+			Containers: []v1.Container{
+				{
+					Name:    "pod-nfs-vol",
+					Image:   imageutils.GetE2EImage(imageutils.BusyBox),
+					Command: []string{"/bin/sh"},
+					Args:    cmdLine,
+					VolumeMounts: []v1.VolumeMount{
+						{
+							Name:      "nfs-vol",
+							MountPath: "/mnt",
+						},
+					},
+					SecurityContext: &v1.SecurityContext{
+						Privileged: &isPrivileged,
+					},
+				},
+			},
+			RestartPolicy: v1.RestartPolicyNever, //don't restart pod
+			Volumes: []v1.Volume{
+				{
+					Name: "nfs-vol",
+					VolumeSource: v1.VolumeSource{
+						NFS: &v1.NFSVolumeSource{
+							Server:   nfsIP,
+							Path:     "/exports",
+							ReadOnly: false,
+						},
+					},
+				},
+			},
+		},
+	}
+
+	file := staticPodPath(dir, name, ns)
+	f, err := os.OpenFile(file, os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0666)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	y := printers.YAMLPrinter{}
+	y.PrintObj(pod, f)
+
+	return nil
+}
+
 func staticPodPath(dir, name, namespace string) string {
 	return filepath.Join(dir, namespace+"-"+name+".yaml")
 }

test/e2e_node/remote/node_e2e.go

@@ -87,15 +87,6 @@ func (n *NodeE2ERemote) SetupTestPackage(tardir, systemSpecName string) error {
 	return nil
 }
 
-// prependCOSMounterFlag prepends the flag for setting the GCI mounter path to
-// args and returns the result.
-func prependCOSMounterFlag(args, host, workspace string) (string, error) {
-	klog.V(2).Infof("GCI/COS node and GCI/COS mounter both detected, modifying --experimental-mounter-path accordingly")
-	mounterPath := filepath.Join(workspace, "mounter")
-	args = fmt.Sprintf("--kubelet-flags=--experimental-mounter-path=%s ", mounterPath) + args
-	return args, nil
-}
-
 // prependMemcgNotificationFlag prepends the flag for enabling memcg
 // notification to args and returns the result.
 func prependMemcgNotificationFlag(args string) string {
@@ -124,8 +115,7 @@ func osSpecificActions(args, host, workspace string) (string, error) {
 		return args, setKubeletSELinuxLabels(host, workspace)
 	case strings.Contains(output, "gci"), strings.Contains(output, "cos"):
 		args = prependMemcgNotificationFlag(args)
-		args = prependGCPCredentialProviderFlag(args, workspace)
-		return prependCOSMounterFlag(args, host, workspace)
+		return prependGCPCredentialProviderFlag(args, workspace), nil
 	case strings.Contains(output, "ubuntu"):
 		args = prependGCPCredentialProviderFlag(args, workspace)
 		return prependMemcgNotificationFlag(args), nil