Add test for starting kubelet with a CSI volume mounted

test/e2e/storage/static_pods.go

@@ -0,0 +1,159 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package storage
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"github.com/onsi/ginkgo/v2"
+	"github.com/onsi/gomega"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/kubernetes/test/e2e/framework"
+	e2epod "k8s.io/kubernetes/test/e2e/framework/pod"
+	e2evolume "k8s.io/kubernetes/test/e2e/framework/volume"
+	"k8s.io/kubernetes/test/e2e/storage/drivers"
+	storageframework "k8s.io/kubernetes/test/e2e/storage/framework"
+	"k8s.io/kubernetes/test/e2e/storage/utils"
+	admissionapi "k8s.io/pod-security-admission/api"
+)
+
+// Tests for static Pods + CSI volume reconstruction.
+//
+// NOTE: these tests *require* the cluster under test to be Kubernetes In Docker (kind)!
+// Kind runs its API server as a static Pod, and we leverage it here
+// to test kubelet starting without the API server.
+var _ = utils.SIGDescribe("StaticPods [Feature:Kind]", func() {
+	f := framework.NewDefaultFramework("static-pods-csi")
+	f.NamespacePodSecurityEnforceLevel = admissionapi.LevelPrivileged
+
+	// global vars for the ginkgo.BeforeEach() / It()'s below
+	var (
+		driver     storageframework.DynamicPVTestDriver
+		testConfig *storageframework.PerTestConfig
+	)
+
+	ginkgo.BeforeEach(func(ctx context.Context) {
+		// Install a CSI driver. Using csi-driver-hospath here.
+		driver = drivers.InitHostPathCSIDriver().(storageframework.DynamicPVTestDriver)
+		testConfig = driver.PrepareTest(ctx, f)
+	})
+
+	// Test https://github.com/kubernetes/kubernetes/issues/117745
+	// I.e. kubelet starts and it must start the API server as a static pod,
+	// while there is a CSI volume mounted by the previous kubelet.
+	ginkgo.It("should run after kubelet stopped with CSI volume mounted [Disruptive][Serial]", func(ctx context.Context) {
+		var timeout int64 = 5
+
+		ginkgo.By("Provision a new CSI volume")
+		res := storageframework.CreateVolumeResource(ctx, driver, testConfig, storageframework.DefaultFsDynamicPV, e2evolume.SizeRange{Min: "1", Max: "1Gi"})
+		ginkgo.DeferCleanup(func(ctx context.Context) {
+			res.CleanupResource(ctx)
+		})
+
+		ginkgo.By("Run a pod with the volume")
+		podConfig := &e2epod.Config{
+			NS:            f.Namespace.Name,
+			PVCs:          []*v1.PersistentVolumeClaim{res.Pvc},
+			NodeSelection: testConfig.ClientNodeSelection,
+		}
+		pod, err := e2epod.CreateSecPod(ctx, f.ClientSet, podConfig, f.Timeouts.PodStart)
+		framework.ExpectNoError(err, "Creating a pod with a CSI volume")
+		ginkgo.DeferCleanup(f.ClientSet.CoreV1().Pods(f.Namespace.Name).Delete, pod.Name, metav1.DeleteOptions{})
+
+		ginkgo.By("Stop the control plane by removing the static pod manifests")
+		err = stopControlPlane(ctx)
+		framework.ExpectNoError(err, "Stopping the control plane")
+
+		ginkgo.By("Wait for the API server to disappear")
+		gomega.Eventually(ctx, func(ctx context.Context) error {
+			_, err := f.ClientSet.StorageV1().StorageClasses().List(ctx, metav1.ListOptions{TimeoutSeconds: &timeout})
+			return err
+		}).WithTimeout(time.Minute).Should(gomega.Not(gomega.Succeed()))
+
+		ginkgo.By("Stop kubelet")
+		err = stopKindKubelet(ctx)
+		framework.ExpectNoError(err, "Stopping kubelet")
+
+		ginkgo.By("Re-enable control plane")
+		err = enableControlPlane(ctx)
+		framework.ExpectNoError(err, "Re-enabling control plane by restoring the static pod manifests")
+
+		ginkgo.By("Start kubelet")
+		err = startKindKubelet(ctx)
+		framework.ExpectNoError(err, "Starting kubelet")
+
+		ginkgo.By("Wait for a static pod with the API server to start")
+		const apiServerStartTimeout = 10 * time.Minute // It takes up to 2 minutes on my machine
+		gomega.Eventually(ctx, func(ctx context.Context) error {
+			_, err := f.ClientSet.StorageV1().StorageClasses().List(ctx, metav1.ListOptions{TimeoutSeconds: &timeout})
+			return err
+		}).WithTimeout(apiServerStartTimeout).Should(gomega.Succeed())
+	})
+})
+
+func stopKindKubelet(ctx context.Context) error {
+	return kubeletExec("systemctl", "stop", "kubelet")
+}
+
+func startKindKubelet(ctx context.Context) error {
+	return kubeletExec("systemctl", "start", "kubelet")
+}
+
+func stopControlPlane(ctx context.Context) error {
+	// Move all static pod manifests to a backup dir (incl. KCM, scheduler, API server and etcd)
+	return kubeletExec("sh", "-c", "mkdir -p /etc/kubernetes/manifests-backup && mv /etc/kubernetes/manifests/* /etc/kubernetes/manifests-backup/")
+}
+
+func enableControlPlane(ctx context.Context) error {
+	// Restore the static pod manifests from the backup dir.
+	// Using `sh` to get `*` expansion.
+	return kubeletExec("sh", "-c", "mv /etc/kubernetes/manifests-backup/* /etc/kubernetes/manifests/")
+}
+
+// Run a command in container with kubelet (and the whole control plane as containers)
+func kubeletExec(command ...string) error {
+	containerName := getKindContainerName()
+	args := []string{"exec", containerName}
+	args = append(args, command...)
+	cmd := exec.Command("docker", args...)
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("command %q failed: %v\noutput:%s", prettyCmd(cmd), err, string(out))
+	}
+
+	framework.Logf("command %q succeeded:\n%s", prettyCmd(cmd), string(out))
+	return nil
+}
+
+func getKindContainerName() string {
+	clusterName := os.Getenv("KIND_CLUSTER_NAME")
+	if clusterName == "" {
+		clusterName = "kind"
+	}
+	return clusterName + "-control-plane"
+}
+
+func prettyCmd(cmd *exec.Cmd) string {
+	return fmt.Sprintf("%s %s", cmd.Path, strings.Join(cmd.Args, " "))
+}