k8s.io/kubernetes@v1.29.3/test/e2e_node/node_shutdown_linux_test.go

//go:build linux
// +build linux

/*
Copyright 2021 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 e2enode

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strconv"
	"time"

	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/fields"
	"k8s.io/apimachinery/pkg/watch"
	"k8s.io/client-go/tools/cache"
	watchtools "k8s.io/client-go/tools/watch"
	"k8s.io/kubectl/pkg/util/podutils"

	admissionapi "k8s.io/pod-security-admission/api"

	"github.com/onsi/ginkgo/v2"
	"github.com/onsi/gomega"
	"k8s.io/kubernetes/pkg/apis/scheduling"
	"k8s.io/kubernetes/test/e2e/framework"
	e2epod "k8s.io/kubernetes/test/e2e/framework/pod"
	e2eskipper "k8s.io/kubernetes/test/e2e/framework/skipper"
	"k8s.io/kubernetes/test/e2e/nodefeature"

	"github.com/godbus/dbus/v5"
	v1 "k8s.io/api/core/v1"
	schedulingv1 "k8s.io/api/scheduling/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/uuid"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/kubernetes/pkg/features"
	kubeletconfig "k8s.io/kubernetes/pkg/kubelet/apis/config"
	kubelettypes "k8s.io/kubernetes/pkg/kubelet/types"
	testutils "k8s.io/kubernetes/test/utils"
)

var _ = SIGDescribe("GracefulNodeShutdown", framework.WithSerial(), nodefeature.GracefulNodeShutdown, nodefeature.GracefulNodeShutdownBasedOnPodPriority, func() {
	f := framework.NewDefaultFramework("graceful-node-shutdown")
	f.NamespacePodSecurityLevel = admissionapi.LevelPrivileged

	ginkgo.BeforeEach(func() {
		if _, err := exec.LookPath("systemd-run"); err == nil {
			if version, verr := exec.Command("systemd-run", "--version").Output(); verr == nil {
				// sample output from $ systemd-run --version
				// systemd 245 (245.4-4ubuntu3.13)
				re := regexp.MustCompile(`systemd (\d+)`)
				if match := re.FindSubmatch(version); len(match) > 1 {
					systemdVersion, err := strconv.Atoi(string(match[1]))
					if err != nil {
						framework.Logf("failed to parse systemd version with error %v, 'systemd-run --version' output was [%s]", err, version)
					} else {
						// See comments in issue 107043, this is a known problem for a long time that this feature does not work on older systemd
						// https://github.com/kubernetes/kubernetes/issues/107043#issuecomment-997546598
						if systemdVersion < 245 {
							e2eskipper.Skipf("skipping GracefulNodeShutdown tests as we are running on an old version of systemd : %d", systemdVersion)
						}
					}
				}
			}
		}
	})

	f.Context("graceful node shutdown when PodDisruptionConditions are enabled", nodefeature.PodDisruptionConditions, func() {

		const (
			pollInterval            = 1 * time.Second
			podStatusUpdateTimeout  = 30 * time.Second
			nodeStatusUpdateTimeout = 30 * time.Second
			nodeShutdownGracePeriod = 30 * time.Second
		)

		tempSetCurrentKubeletConfig(f, func(ctx context.Context, initialConfig *kubeletconfig.KubeletConfiguration) {
			initialConfig.FeatureGates = map[string]bool{
				string(features.GracefulNodeShutdown):                   true,
				string(features.PodDisruptionConditions):                true,
				string(features.GracefulNodeShutdownBasedOnPodPriority): false,
			}
			initialConfig.ShutdownGracePeriod = metav1.Duration{Duration: nodeShutdownGracePeriod}
		})

		ginkgo.BeforeEach(func(ctx context.Context) {
			ginkgo.By("Wait for the node to be ready")
			waitForNodeReady(ctx)
		})

		ginkgo.AfterEach(func() {
			ginkgo.By("Emitting Shutdown false signal; cancelling the shutdown")
			err := emitSignalPrepareForShutdown(false)
			framework.ExpectNoError(err)
		})

		ginkgo.It("should add the DisruptionTarget pod failure condition to the evicted pods", func(ctx context.Context) {
			nodeName := getNodeName(ctx, f)
			nodeSelector := fields.Set{
				"spec.nodeName": nodeName,
			}.AsSelector().String()

			// Define test pods
			pods := []*v1.Pod{
				getGracePeriodOverrideTestPod("pod-to-evict-"+string(uuid.NewUUID()), nodeName, 5, ""),
			}

			ctx, cancel := context.WithCancel(context.Background())
			defer cancel()

			ginkgo.By("reating batch pods")
			e2epod.NewPodClient(f).CreateBatch(ctx, pods)

			list, err := e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
				FieldSelector: nodeSelector,
			})

			framework.ExpectNoError(err)
			gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")

			list, err = e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
				FieldSelector: nodeSelector,
			})
			if err != nil {
				framework.Failf("Failed to start batch pod: %q", err)
			}
			gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")

			for _, pod := range list.Items {
				framework.Logf("Pod (%v/%v) status conditions: %q", pod.Namespace, pod.Name, &pod.Status.Conditions)
			}

			ginkgo.By("Verifying batch pods are running")
			for _, pod := range list.Items {
				if podReady, err := testutils.PodRunningReady(&pod); err != nil || !podReady {
					framework.Failf("Failed to start batch pod: (%v/%v)", pod.Namespace, pod.Name)
				}
			}

			ginkgo.By("Emitting shutdown signal")
			err = emitSignalPrepareForShutdown(true)
			framework.ExpectNoError(err)

			ginkgo.By("Verifying that all pods are shutdown")
			// All pod should be shutdown
			gomega.Eventually(func() error {
				list, err = e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
					FieldSelector: nodeSelector,
				})
				if err != nil {
					return err
				}
				gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")

				for _, pod := range list.Items {
					if !isPodShutdown(&pod) {
						framework.Logf("Expecting pod to be shutdown, but it's not currently. Pod: (%v/%v), Pod Status Phase: %q, Pod Status Reason: %q", pod.Namespace, pod.Name, pod.Status.Phase, pod.Status.Reason)
						return fmt.Errorf("pod should be shutdown, phase: %s", pod.Status.Phase)
					}
					podDisruptionCondition := e2epod.FindPodConditionByType(&pod.Status, v1.DisruptionTarget)
					if podDisruptionCondition == nil {
						framework.Failf("pod (%v/%v) should have the condition: %q, pod status: %v", pod.Namespace, pod.Name, v1.DisruptionTarget, pod.Status)
					}
				}
				return nil
			}, podStatusUpdateTimeout+(nodeShutdownGracePeriod), pollInterval).Should(gomega.BeNil())
		})
	})

	ginkgo.Context("when gracefully shutting down", func() {

		const (
			pollInterval                        = 1 * time.Second
			podStatusUpdateTimeout              = 30 * time.Second
			nodeStatusUpdateTimeout             = 30 * time.Second
			nodeShutdownGracePeriod             = 20 * time.Second
			nodeShutdownGracePeriodCriticalPods = 10 * time.Second
		)

		tempSetCurrentKubeletConfig(f, func(ctx context.Context, initialConfig *kubeletconfig.KubeletConfiguration) {
			initialConfig.FeatureGates = map[string]bool{
				string(features.GracefulNodeShutdown):                   true,
				string(features.GracefulNodeShutdownBasedOnPodPriority): false,
				string(features.PodReadyToStartContainersCondition):     true,
			}
			initialConfig.ShutdownGracePeriod = metav1.Duration{Duration: nodeShutdownGracePeriod}
			initialConfig.ShutdownGracePeriodCriticalPods = metav1.Duration{Duration: nodeShutdownGracePeriodCriticalPods}
		})

		ginkgo.BeforeEach(func(ctx context.Context) {
			ginkgo.By("Wait for the node to be ready")
			waitForNodeReady(ctx)
		})

		ginkgo.AfterEach(func(ctx context.Context) {
			ginkgo.By("Emitting Shutdown false signal; cancelling the shutdown")
			err := emitSignalPrepareForShutdown(false)
			framework.ExpectNoError(err)
		})

		ginkgo.It("should be able to gracefully shutdown pods with various grace periods", func(ctx context.Context) {
			nodeName := getNodeName(ctx, f)
			nodeSelector := fields.Set{
				"spec.nodeName": nodeName,
			}.AsSelector().String()

			// Define test pods
			pods := []*v1.Pod{
				getGracePeriodOverrideTestPod("period-120-"+string(uuid.NewUUID()), nodeName, 120, ""),
				getGracePeriodOverrideTestPod("period-5-"+string(uuid.NewUUID()), nodeName, 5, ""),
				getGracePeriodOverrideTestPod("period-critical-120-"+string(uuid.NewUUID()), nodeName, 120, scheduling.SystemNodeCritical),
				getGracePeriodOverrideTestPod("period-critical-5-"+string(uuid.NewUUID()), nodeName, 5, scheduling.SystemNodeCritical),
			}

			ginkgo.By("Creating batch pods")
			e2epod.NewPodClient(f).CreateBatch(ctx, pods)

			list, err := e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
				FieldSelector: nodeSelector,
			})
			framework.ExpectNoError(err)
			gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")

			ctx, cancel := context.WithCancel(ctx)
			defer cancel()
			go func() {
				defer ginkgo.GinkgoRecover()
				w := &cache.ListWatch{
					WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
						return f.ClientSet.CoreV1().Pods(f.Namespace.Name).Watch(ctx, options)
					},
				}

				// Setup watch to continuously monitor any pod events and detect invalid pod status updates
				_, err = watchtools.Until(ctx, list.ResourceVersion, w, func(event watch.Event) (bool, error) {
					if pod, ok := event.Object.(*v1.Pod); ok {
						if isPodStatusAffectedByIssue108594(pod) {
							return false, fmt.Errorf("failing test due to detecting invalid pod status")
						}
						// Watch will never terminate (only when the test ends due to context cancellation)
						return false, nil
					}
					return false, nil
				})

				// Ignore timeout error since the context will be explicitly cancelled and the watch will never return true
				if err != nil && err != wait.ErrWaitTimeout {
					framework.Failf("watch for invalid pod status failed: %v", err.Error())
				}
			}()

			ginkgo.By("Verifying batch pods are running")
			for _, pod := range list.Items {
				if podReady, err := testutils.PodRunningReady(&pod); err != nil || !podReady {
					framework.Failf("Failed to start batch pod: %v", pod.Name)
				}
			}

			ginkgo.By("Emitting shutdown signal")
			err = emitSignalPrepareForShutdown(true)
			framework.ExpectNoError(err)

			ginkgo.By("Verifying that non-critical pods are shutdown")
			// Not critical pod should be shutdown
			gomega.Eventually(ctx, func(ctx context.Context) error {
				list, err = e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
					FieldSelector: nodeSelector,
				})
				if err != nil {
					return err
				}
				gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")

				for _, pod := range list.Items {
					if kubelettypes.IsCriticalPod(&pod) {
						if isPodShutdown(&pod) {
							framework.Logf("Expecting critical pod (%v/%v) to be running, but it's not currently. Pod Status %+v", pod.Namespace, pod.Name, pod.Status)
							return fmt.Errorf("critical pod (%v/%v) should not be shutdown, phase: %s", pod.Namespace, pod.Name, pod.Status.Phase)
						}
					} else {
						if !isPodShutdown(&pod) {
							framework.Logf("Expecting non-critical pod (%v/%v) to be shutdown, but it's not currently. Pod Status %+v", pod.Name, pod.Status)
							return fmt.Errorf("pod (%v/%v) should be shutdown, phase: %s", pod.Namespace, pod.Name, pod.Status.Phase)
						}
					}
				}
				return nil
			}, podStatusUpdateTimeout, pollInterval).Should(gomega.Succeed())

			ginkgo.By("Verifying that all pods are shutdown")
			// All pod should be shutdown
			gomega.Eventually(ctx, func(ctx context.Context) error {
				list, err = e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
					FieldSelector: nodeSelector,
				})
				if err != nil {
					return err
				}
				gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")

				for _, pod := range list.Items {
					if !isPodShutdown(&pod) {
						framework.Logf("Expecting pod (%v/%v) to be shutdown, but it's not currently: Pod Status %+v", pod.Namespace, pod.Name, pod.Status)
						return fmt.Errorf("pod (%v/%v) should be shutdown, phase: %s", pod.Namespace, pod.Name, pod.Status.Phase)
					}
				}
				return nil
			},
				// Critical pod starts shutdown after (nodeShutdownGracePeriod-nodeShutdownGracePeriodCriticalPods)
				podStatusUpdateTimeout+(nodeShutdownGracePeriod-nodeShutdownGracePeriodCriticalPods),
				pollInterval).Should(gomega.Succeed())

			ginkgo.By("Verify that all pod ready to start condition are set to false after terminating")
			// All pod ready to start condition should set to false
			gomega.Eventually(ctx, func(ctx context.Context) error {
				list, err = e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
					FieldSelector: nodeSelector,
				})
				if err != nil {
					return err
				}
				gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)))
				for _, pod := range list.Items {
					if !isPodReadyToStartConditionSetToFalse(&pod) {
						framework.Logf("Expecting pod (%v/%v) 's ready to start condition set to false, "+
							"but it's not currently: Pod Condition %+v", pod.Namespace, pod.Name, pod.Status.Conditions)
						return fmt.Errorf("pod (%v/%v) 's ready to start condition should be false, condition: %s, phase: %s",
							pod.Namespace, pod.Name, pod.Status.Conditions, pod.Status.Phase)
					}
				}
				return nil
			},
			).Should(gomega.Succeed())
		})

		ginkgo.It("should be able to handle a cancelled shutdown", func(ctx context.Context) {
			ginkgo.By("Emitting Shutdown signal")
			err := emitSignalPrepareForShutdown(true)
			framework.ExpectNoError(err)
			gomega.Eventually(ctx, func(ctx context.Context) error {
				isReady := getNodeReadyStatus(ctx, f)
				if isReady {
					return fmt.Errorf("node did not become shutdown as expected")
				}
				return nil
			}, nodeStatusUpdateTimeout, pollInterval).Should(gomega.Succeed())

			ginkgo.By("Emitting Shutdown false signal; cancelling the shutdown")
			err = emitSignalPrepareForShutdown(false)
			framework.ExpectNoError(err)
			gomega.Eventually(ctx, func(ctx context.Context) error {
				isReady := getNodeReadyStatus(ctx, f)
				if !isReady {
					return fmt.Errorf("node did not recover as expected")
				}
				return nil
			}, nodeStatusUpdateTimeout, pollInterval).Should(gomega.Succeed())
		})
	})

	ginkgo.Context("when gracefully shutting down with Pod priority", func() {

		const (
			pollInterval                 = 1 * time.Second
			podStatusUpdateTimeout       = 30 * time.Second
			priorityClassesCreateTimeout = 10 * time.Second
		)

		var (
			customClassA = getPriorityClass("custom-class-a", 100000)
			customClassB = getPriorityClass("custom-class-b", 10000)
			customClassC = getPriorityClass("custom-class-c", 1000)
		)

		tempSetCurrentKubeletConfig(f, func(ctx context.Context, initialConfig *kubeletconfig.KubeletConfiguration) {
			initialConfig.FeatureGates = map[string]bool{
				string(features.GracefulNodeShutdown):                   true,
				string(features.GracefulNodeShutdownBasedOnPodPriority): true,
			}
			initialConfig.ShutdownGracePeriodByPodPriority = []kubeletconfig.ShutdownGracePeriodByPodPriority{
				{
					Priority:                   scheduling.SystemCriticalPriority,
					ShutdownGracePeriodSeconds: int64(podStatusUpdateTimeout / time.Second),
				},
				{
					Priority:                   customClassA.Value,
					ShutdownGracePeriodSeconds: int64(podStatusUpdateTimeout / time.Second),
				},
				{
					Priority:                   customClassB.Value,
					ShutdownGracePeriodSeconds: int64(podStatusUpdateTimeout / time.Second),
				},
				{
					Priority:                   customClassC.Value,
					ShutdownGracePeriodSeconds: int64(podStatusUpdateTimeout / time.Second),
				},
				{
					Priority:                   scheduling.DefaultPriorityWhenNoDefaultClassExists,
					ShutdownGracePeriodSeconds: int64(podStatusUpdateTimeout / time.Second),
				},
			}

		})

		ginkgo.BeforeEach(func(ctx context.Context) {
			ginkgo.By("Wait for the node to be ready")
			waitForNodeReady(ctx)
			customClasses := []*schedulingv1.PriorityClass{customClassA, customClassB, customClassC}
			for _, customClass := range customClasses {
				_, err := f.ClientSet.SchedulingV1().PriorityClasses().Create(ctx, customClass, metav1.CreateOptions{})
				if err != nil && !apierrors.IsAlreadyExists(err) {
					framework.ExpectNoError(err)
				}
			}
			gomega.Eventually(ctx, func(ctx context.Context) error {
				for _, customClass := range customClasses {
					_, err := f.ClientSet.SchedulingV1().PriorityClasses().Get(ctx, customClass.Name, metav1.GetOptions{})
					if err != nil {
						return err
					}
				}
				return nil
			}, priorityClassesCreateTimeout, pollInterval).Should(gomega.Succeed())
		})

		ginkgo.AfterEach(func() {
			ginkgo.By("Emitting Shutdown false signal; cancelling the shutdown")
			err := emitSignalPrepareForShutdown(false)
			framework.ExpectNoError(err)
		})

		ginkgo.It("should be able to gracefully shutdown pods with various grace periods", func(ctx context.Context) {
			nodeName := getNodeName(ctx, f)
			nodeSelector := fields.Set{
				"spec.nodeName": nodeName,
			}.AsSelector().String()

			var (
				period5Name         = "period-5-" + string(uuid.NewUUID())
				periodC5Name        = "period-c-5-" + string(uuid.NewUUID())
				periodB5Name        = "period-b-5-" + string(uuid.NewUUID())
				periodA5Name        = "period-a-5-" + string(uuid.NewUUID())
				periodCritical5Name = "period-critical-5-" + string(uuid.NewUUID())
			)

			// Define test pods
			pods := []*v1.Pod{
				getGracePeriodOverrideTestPod(period5Name, nodeName, 5, ""),
				getGracePeriodOverrideTestPod(periodC5Name, nodeName, 5, customClassC.Name),
				getGracePeriodOverrideTestPod(periodB5Name, nodeName, 5, customClassB.Name),
				getGracePeriodOverrideTestPod(periodA5Name, nodeName, 5, customClassA.Name),
				getGracePeriodOverrideTestPod(periodCritical5Name, nodeName, 5, scheduling.SystemNodeCritical),
			}

			// Expected down steps
			downSteps := [][]string{
				{
					period5Name,
				},
				{
					period5Name,
					periodC5Name,
				},
				{

					period5Name,
					periodC5Name,
					periodB5Name,
				},
				{
					period5Name,
					periodC5Name,
					periodB5Name,
					periodA5Name,
				},
				{
					period5Name,
					periodC5Name,
					periodB5Name,
					periodA5Name,
					periodCritical5Name,
				},
			}

			ginkgo.By("Creating batch pods")
			e2epod.NewPodClient(f).CreateBatch(ctx, pods)

			list, err := e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
				FieldSelector: nodeSelector,
			})
			framework.ExpectNoError(err)
			gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")

			ginkgo.By("Verifying batch pods are running")
			for _, pod := range list.Items {
				if podReady, err := testutils.PodRunningReady(&pod); err != nil || !podReady {
					framework.Failf("Failed to start batch pod: (%v/%v)", pod.Namespace, pod.Name)
				}
			}

			ginkgo.By("Emitting shutdown signal")
			err = emitSignalPrepareForShutdown(true)
			framework.ExpectNoError(err)

			ginkgo.By("Verifying that pods are shutdown")

			for _, step := range downSteps {
				gomega.Eventually(ctx, func(ctx context.Context) error {
					list, err = e2epod.NewPodClient(f).List(ctx, metav1.ListOptions{
						FieldSelector: nodeSelector,
					})
					if err != nil {
						return err
					}
					gomega.Expect(list.Items).To(gomega.HaveLen(len(pods)), "the number of pods is not as expected")
					for _, pod := range list.Items {
						shouldShutdown := false
						for _, podName := range step {
							if podName == pod.Name {
								shouldShutdown = true
								break
							}
						}
						if !shouldShutdown {
							if pod.Status.Phase != v1.PodRunning {
								framework.Logf("Expecting pod to be running, but it's not currently. Pod: (%v/%v), Pod Status Phase: %q, Pod Status Reason: %q", pod.Namespace, pod.Name, pod.Status.Phase, pod.Status.Reason)
								return fmt.Errorf("pod (%v/%v) should not be shutdown, phase: %s, reason: %s", pod.Namespace, pod.Name, pod.Status.Phase, pod.Status.Reason)
							}
						} else {
							if pod.Status.Reason != podShutdownReason {
								framework.Logf("Expecting pod to be shutdown, but it's not currently. Pod: (%v/%v), Pod Status Phase: %q, Pod Status Reason: %q", pod.Namespace, pod.Name, pod.Status.Phase, pod.Status.Reason)
								for _, item := range list.Items {
									framework.Logf("DEBUG %s, %s, %s", item.Name, item.Status.Phase, pod.Status.Reason)
								}
								return fmt.Errorf("pod (%v/%v) should be shutdown, reason: %s", pod.Namespace, pod.Name, pod.Status.Reason)
							}
						}
					}
					return nil
				}, podStatusUpdateTimeout, pollInterval).Should(gomega.Succeed())
			}

			ginkgo.By("should have state file")
			stateFile := "/var/lib/kubelet/graceful_node_shutdown_state"
			_, err = os.Stat(stateFile)
			framework.ExpectNoError(err)
		})
	})
})

func getPriorityClass(name string, value int32) *schedulingv1.PriorityClass {
	priority := &schedulingv1.PriorityClass{
		TypeMeta: metav1.TypeMeta{
			Kind:       "PriorityClass",
			APIVersion: "scheduling.k8s.io/v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name: name,
		},
		Value: value,
	}
	return priority
}

// getGracePeriodOverrideTestPod returns a new Pod object containing a container
// runs a shell script, hangs the process until a SIGTERM signal is received.
// The script waits for $PID to ensure that the process does not exist.
// If priorityClassName is scheduling.SystemNodeCritical, the Pod is marked as critical and a comment is added.
func getGracePeriodOverrideTestPod(name string, node string, gracePeriod int64, priorityClassName string) *v1.Pod {
	pod := &v1.Pod{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Pod",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name: name,
		},
		Spec: v1.PodSpec{
			Containers: []v1.Container{
				{
					Name:    name,
					Image:   busyboxImage,
					Command: []string{"sh", "-c"},
					Args: []string{`
					sleep 9999999 &
					PID=$!
					_term() {
						echo "Caught SIGTERM signal!"
						wait $PID
					}
					
					trap _term SIGTERM
					wait $PID
					`},
				},
			},
			TerminationGracePeriodSeconds: &gracePeriod,
			NodeName:                      node,
		},
	}
	if priorityClassName == scheduling.SystemNodeCritical {
		pod.ObjectMeta.Annotations = map[string]string{
			kubelettypes.ConfigSourceAnnotationKey: kubelettypes.FileSource,
		}
		pod.Spec.PriorityClassName = priorityClassName
		if !kubelettypes.IsCriticalPod(pod) {
			framework.Failf("pod %q should be a critical pod", pod.Name)
		}
	} else {
		pod.Spec.PriorityClassName = priorityClassName
		if kubelettypes.IsCriticalPod(pod) {
			framework.Failf("pod %q should not be a critical pod", pod.Name)
		}
	}
	return pod
}

// Emits a fake PrepareForShutdown dbus message on system dbus. Will cause kubelet to react to an active shutdown event.
func emitSignalPrepareForShutdown(b bool) error {
	conn, err := dbus.ConnectSystemBus()
	if err != nil {
		return err
	}
	defer conn.Close()
	return conn.Emit("/org/freedesktop/login1", "org.freedesktop.login1.Manager.PrepareForShutdown", b)
}

func getNodeReadyStatus(ctx context.Context, f *framework.Framework) bool {
	nodeList, err := f.ClientSet.CoreV1().Nodes().List(ctx, metav1.ListOptions{})
	framework.ExpectNoError(err)
	// Assuming that there is only one node, because this is a node e2e test.
	gomega.Expect(nodeList.Items).To(gomega.HaveLen(1), "the number of nodes is not as expected")
	return isNodeReady(&nodeList.Items[0])
}

func systemctlDaemonReload() error {
	cmd := "systemctl daemon-reload"
	_, err := runCommand("sh", "-c", cmd)
	return err
}

var (
	dbusConfPath = "/etc/systemd/system/dbus.service.d/k8s-graceful-node-shutdown-e2e.conf"
	dbusConf     = `
[Unit]
RefuseManualStart=no
RefuseManualStop=no
[Service]
KillMode=control-group
ExecStop=
`
)

func overlayDbusConfig() error {
	err := os.MkdirAll(filepath.Dir(dbusConfPath), 0755)
	if err != nil {
		return err
	}
	err = os.WriteFile(dbusConfPath, []byte(dbusConf), 0644)
	if err != nil {
		return err
	}
	return systemctlDaemonReload()
}

func restoreDbusConfig() error {
	err := os.Remove(dbusConfPath)
	if err != nil {
		return err
	}
	return systemctlDaemonReload()
}

const (
	// https://github.com/kubernetes/kubernetes/blob/1dd781ddcad454cc381806fbc6bd5eba8fa368d7/pkg/kubelet/nodeshutdown/nodeshutdown_manager_linux.go#L43-L44
	podShutdownReason  = "Terminated"
	podShutdownMessage = "Pod was terminated in response to imminent node shutdown."
)

func isPodShutdown(pod *v1.Pod) bool {
	if pod == nil {
		return false
	}

	hasContainersNotReadyCondition := false
	for _, cond := range pod.Status.Conditions {
		if cond.Type == v1.ContainersReady && cond.Status == v1.ConditionFalse {
			hasContainersNotReadyCondition = true
		}
	}

	return pod.Status.Message == podShutdownMessage && pod.Status.Reason == podShutdownReason && hasContainersNotReadyCondition && pod.Status.Phase == v1.PodFailed
}

// Pods should never report failed phase and have ready condition = true (https://github.com/kubernetes/kubernetes/issues/108594)
func isPodStatusAffectedByIssue108594(pod *v1.Pod) bool {
	return pod.Status.Phase == v1.PodFailed && podutils.IsPodReady(pod)
}

func isPodReadyToStartConditionSetToFalse(pod *v1.Pod) bool {
	if pod == nil {
		return false
	}
	readyToStartConditionSetToFalse := false
	for _, cond := range pod.Status.Conditions {
		if cond.Status == v1.ConditionFalse {
			readyToStartConditionSetToFalse = true
		}
	}

	return readyToStartConditionSetToFalse
}