Introduce RequestEviction feature for evicting pods in background

When the feature is enabled each pod with descheduler.alpha.kubernetes.io/request-evict-only
annotation will have the eviction API error examined for a specific
error code/reason and message. If matched eviction of such a pod will be interpreted
as initiation of an eviction in background.

test/e2e/e2e_evictioninbackground_test.go

@@ -0,0 +1,542 @@
+package e2e
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/wait"
+	clientset "k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/clientcmd"
+	componentbaseconfig "k8s.io/component-base/config"
+	"k8s.io/klog/v2"
+	utilptr "k8s.io/utils/ptr"
+
+	kvcorev1 "kubevirt.io/api/core/v1"
+	generatedclient "kubevirt.io/client-go/generated/kubevirt/clientset/versioned"
+
+	"sigs.k8s.io/descheduler/pkg/api"
+	apiv1alpha2 "sigs.k8s.io/descheduler/pkg/api/v1alpha2"
+	"sigs.k8s.io/descheduler/pkg/descheduler/client"
+	"sigs.k8s.io/descheduler/pkg/framework/plugins/defaultevictor"
+	"sigs.k8s.io/descheduler/pkg/framework/plugins/podlifetime"
+)
+
+const (
+	vmiCount = 3
+)
+
+func virtualMachineInstance(idx int) *kvcorev1.VirtualMachineInstance {
+	return &kvcorev1.VirtualMachineInstance{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: fmt.Sprintf("kubevirtvmi-%v", idx),
+			Annotations: map[string]string{
+				"descheduler.alpha.kubernetes.io/request-evict-only": "",
+			},
+		},
+		Spec: kvcorev1.VirtualMachineInstanceSpec{
+			EvictionStrategy: utilptr.To[kvcorev1.EvictionStrategy](kvcorev1.EvictionStrategyLiveMigrate),
+			Domain: kvcorev1.DomainSpec{
+				Devices: kvcorev1.Devices{
+					AutoattachPodInterface: utilptr.To[bool](false),
+					Disks: []kvcorev1.Disk{
+						{
+							Name: "containerdisk",
+							DiskDevice: kvcorev1.DiskDevice{
+								Disk: &kvcorev1.DiskTarget{
+									Bus: kvcorev1.DiskBusVirtio,
+								},
+							},
+						},
+						{
+							Name: "cloudinitdisk",
+							DiskDevice: kvcorev1.DiskDevice{
+								Disk: &kvcorev1.DiskTarget{
+									Bus: kvcorev1.DiskBusVirtio,
+								},
+							},
+						},
+					},
+					Rng: &kvcorev1.Rng{},
+				},
+				Resources: kvcorev1.ResourceRequirements{
+					Requests: v1.ResourceList{
+						v1.ResourceMemory: resource.MustParse("1024M"),
+					},
+				},
+			},
+			TerminationGracePeriodSeconds: utilptr.To[int64](0),
+			Volumes: []kvcorev1.Volume{
+				{
+					Name: "containerdisk",
+					VolumeSource: kvcorev1.VolumeSource{
+						ContainerDisk: &kvcorev1.ContainerDiskSource{
+							Image: "quay.io/kubevirt/fedora-with-test-tooling-container-disk:20240710_1265d1090",
+						},
+					},
+				},
+				{
+					Name: "cloudinitdisk",
+					VolumeSource: kvcorev1.VolumeSource{
+						CloudInitNoCloud: &kvcorev1.CloudInitNoCloudSource{
+							UserData: `#cloud-config
+password: fedora
+chpasswd: { expire: False }
+packages:
+  - nginx
+runcmd:
+  - [ "systemctl", "enable", "--now", "nginx" ]`,
+							NetworkData: `version: 2
+ethernets:
+  eth0:
+    addresses: [ fd10:0:2::2/120 ]
+    dhcp4: true
+    gateway6: fd10:0:2::1`,
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func waitForKubevirtReady(t *testing.T, ctx context.Context, kvClient generatedclient.Interface) {
+	obj, err := kvClient.KubevirtV1().KubeVirts("kubevirt").Get(ctx, "kubevirt", metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("Unable to get kubevirt/kubevirt: %v", err)
+	}
+	available := false
+	for _, condition := range obj.Status.Conditions {
+		if condition.Type == kvcorev1.KubeVirtConditionAvailable {
+			if condition.Status == corev1.ConditionTrue {
+				available = true
+			}
+		}
+	}
+	if !available {
+		t.Fatalf("Kubevirt is not available")
+	}
+	klog.Infof("Kubevirt is available")
+}
+
+func allVMIsHaveRunningPods(t *testing.T, ctx context.Context, kubeClient clientset.Interface, kvClient generatedclient.Interface) (bool, error) {
+	klog.Infof("Checking all vmi active pods are running")
+	uidMap := make(map[types.UID]*corev1.Pod)
+	podList, err := kubeClient.CoreV1().Pods("default").List(ctx, metav1.ListOptions{})
+	if err != nil {
+		if strings.Contains(err.Error(), "client rate limiter") {
+			klog.Infof("Unable to list pods: %v", err)
+			return false, nil
+		}
+		klog.Infof("Unable to list pods: %v", err)
+		return false, err
+	}
+
+	for _, item := range podList.Items {
+		pod := item
+		klog.Infof("item: %#v\n", item.UID)
+		uidMap[item.UID] = &pod
+	}
+
+	vmiList, err := kvClient.KubevirtV1().VirtualMachineInstances("default").List(ctx, metav1.ListOptions{})
+	if err != nil {
+		klog.Infof("Unable to list VMIs: %v", err)
+		return false, err
+	}
+	if len(vmiList.Items) != vmiCount {
+		klog.Infof("Expected %v VMIs, got %v instead", vmiCount, len(vmiList.Items))
+		return false, nil
+	}
+
+	for _, item := range vmiList.Items {
+		atLeastOneVmiIsRunning := false
+		for activePod := range item.Status.ActivePods {
+			if _, exists := uidMap[activePod]; !exists {
+				klog.Infof("Active pod %v not found", activePod)
+				return false, nil
+			}
+			klog.Infof("Checking whether active pod %v (uid=%v) is running", uidMap[activePod].Name, activePod)
+			// ignore completed/failed pods
+			if uidMap[activePod].Status.Phase == corev1.PodFailed || uidMap[activePod].Status.Phase == corev1.PodSucceeded {
+				klog.Infof("Ignoring active pod %v, phase=%v", uidMap[activePod].Name, uidMap[activePod].Status.Phase)
+				continue
+			}
+			if uidMap[activePod].Status.Phase != corev1.PodRunning {
+				klog.Infof("activePod %v is not running: %v\n", uidMap[activePod].Name, uidMap[activePod].Status.Phase)
+				return false, nil
+			}
+			atLeastOneVmiIsRunning = true
+		}
+		if !atLeastOneVmiIsRunning {
+			klog.Infof("vmi %v does not have any activePod running\n", item.Name)
+			return false, nil
+		}
+	}
+
+	return true, nil
+}
+
+func podLifeTimePolicy() *apiv1alpha2.DeschedulerPolicy {
+	return &apiv1alpha2.DeschedulerPolicy{
+		Profiles: []apiv1alpha2.DeschedulerProfile{
+			{
+				Name: "KubeVirtPodLifetimeProfile",
+				PluginConfigs: []apiv1alpha2.PluginConfig{
+					{
+						Name: podlifetime.PluginName,
+						Args: runtime.RawExtension{
+							Object: &podlifetime.PodLifeTimeArgs{
+								MaxPodLifeTimeSeconds: utilptr.To[uint](1), // set it to immediate eviction
+								Namespaces: &api.Namespaces{
+									Include: []string{"default"},
+								},
+							},
+						},
+					},
+					{
+						Name: defaultevictor.PluginName,
+						Args: runtime.RawExtension{
+							Object: &defaultevictor.DefaultEvictorArgs{
+								EvictLocalStoragePods: true,
+							},
+						},
+					},
+				},
+				Plugins: apiv1alpha2.Plugins{
+					Filter: apiv1alpha2.PluginSet{
+						Enabled: []string{
+							defaultevictor.PluginName,
+						},
+					},
+					Deschedule: apiv1alpha2.PluginSet{
+						Enabled: []string{
+							podlifetime.PluginName,
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func kVirtRunningPodNames(t *testing.T, ctx context.Context, kubeClient clientset.Interface) []string {
+	names := []string{}
+	if err := wait.PollUntilContextTimeout(ctx, 5*time.Second, 60*time.Second, true, func(ctx context.Context) (bool, error) {
+		podList, err := kubeClient.CoreV1().Pods("default").List(ctx, metav1.ListOptions{})
+		if err != nil {
+			if isClientRateLimiterError(err) {
+				t.Log(err)
+				return false, nil
+			}
+			klog.Infof("Unable to list pods: %v", err)
+			return false, err
+		}
+
+		for _, item := range podList.Items {
+			if !strings.HasPrefix(item.Name, "virt-launcher-kubevirtvmi-") {
+				t.Fatalf("Only pod names with 'virt-launcher-kubevirtvmi-' prefix are expected, got %q instead", item.Name)
+			}
+			if item.Status.Phase == corev1.PodRunning {
+				names = append(names, item.Name)
+			}
+		}
+
+		return true, nil
+	}); err != nil {
+		t.Fatalf("Unable to list running kvirt pod names: %v", err)
+	}
+	return names
+}
+
+func observeLiveMigration(t *testing.T, ctx context.Context, kubeClient clientset.Interface, usedRunningPodNames map[string]struct{}) {
+	prevTotal := uint(0)
+	jumps := 0
+	// keep running the descheduling cycle until the migration is triggered and completed few times or times out
+	for i := 0; i < 240; i++ {
+		// monitor how many pods get evicted
+		names := kVirtRunningPodNames(t, ctx, kubeClient)
+		klog.Infof("vmi pods: %#v\n", names)
+		// The number of pods need to be kept between vmiCount and vmiCount+1.
+		// At most two pods are expected to have virt-launcher-kubevirtvmi-X prefix name in common.
+		prefixes := make(map[string]uint)
+		for _, name := range names {
+			// "virt-launcher-kubevirtvmi-"
+			str := strings.Split(name, "-")[4]
+			prefixes[str]++
+			usedRunningPodNames[name] = struct{}{}
+		}
+
+		hasDouble := false
+		total := uint(0)
+		for idx, count := range prefixes {
+			total += count
+			if count > 2 {
+				t.Fatalf("A vmi kubevirtvmi-%v has more than 2 running active pods (%v), not expected", idx, count)
+			}
+			if count == 2 {
+				if !hasDouble {
+					hasDouble = true
+					continue
+				}
+				t.Fatalf("Another vmi with 2 running active pods, not expected")
+			}
+		}
+		// The total sum can not be higher than vmiCount+1
+		if total > vmiCount+1 {
+			t.Fatalf("Total running pods (%v) are higher than expected vmiCount+1 (%v)", total, vmiCount+1)
+		}
+
+		if prevTotal != 0 && prevTotal != total {
+			jumps++
+		}
+		// Expect at least 3 finished live migrations (two should be enough as well, though ...)
+		if jumps >= 6 {
+			break
+		}
+		prevTotal = total
+		time.Sleep(time.Second)
+	}
+
+	if jumps < 6 {
+		podList, err := kubeClient.CoreV1().Pods("default").List(ctx, metav1.ListOptions{})
+		if err != nil {
+			klog.Infof("Unable to list pods: %v", err)
+		} else {
+			for _, item := range podList.Items {
+				klog.Infof("pod(%v): %#v", item.Name, item)
+			}
+		}
+
+		t.Fatalf("Expected at least 3 finished live migrations, got less: %v", jumps/2.0)
+	}
+	klog.Infof("The live migration finished 3 times")
+
+	// len(usedRunningPodNames) is expected to be vmiCount + jumps/2 + 1 (one more live migration could still be initiated)
+	klog.Infof("len(usedRunningPodNames): %v, upper limit: %v\n", len(usedRunningPodNames), vmiCount+jumps/2+1)
+	if len(usedRunningPodNames) > vmiCount+jumps/2+1 {
+		t.Fatalf("Expected vmiCount + jumps/2 + 1 = %v running pods, got %v instead", vmiCount+jumps/2+1, len(usedRunningPodNames))
+	}
+
+	if err := wait.PollUntilContextTimeout(ctx, 5*time.Second, 60*time.Second, true, func(ctx context.Context) (bool, error) {
+		names := kVirtRunningPodNames(t, ctx, kubeClient)
+		klog.Infof("vmi pods: %#v\n", names)
+		lNames := len(names)
+		if lNames != vmiCount {
+			klog.Infof("Waiting for the number of running vmi pods to be %v, got %v instead", vmiCount, lNames)
+			return false, nil
+		}
+		klog.Infof("The number of running vmi pods is %v as expected", vmiCount)
+		return true, nil
+	}); err != nil {
+		t.Fatalf("Error waiting for %v vmi active pods to be running: %v", vmiCount, err)
+	}
+}
+
+func createAndWaitForDeschedulerRunning(t *testing.T, ctx context.Context, kubeClient clientset.Interface, deschedulerDeploymentObj *appsv1.Deployment) string {
+	klog.Infof("Creating descheduler deployment %v", deschedulerDeploymentObj.Name)
+	_, err := kubeClient.AppsV1().Deployments(deschedulerDeploymentObj.Namespace).Create(ctx, deschedulerDeploymentObj, metav1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating %q deployment: %v", deschedulerDeploymentObj.Name, err)
+	}
+
+	klog.Infof("Waiting for the descheduler pod running")
+	deschedulerPods := waitForPodsRunning(ctx, t, kubeClient, deschedulerDeploymentObj.Labels, 1, deschedulerDeploymentObj.Namespace)
+	if len(deschedulerPods) == 0 {
+		t.Fatalf("Error waiting for %q deployment: no running pod found", deschedulerDeploymentObj.Name)
+	}
+	return deschedulerPods[0].Name
+}
+
+func updateDeschedulerPolicy(t *testing.T, ctx context.Context, kubeClient clientset.Interface, policy *apiv1alpha2.DeschedulerPolicy) {
+	deschedulerPolicyConfigMapObj, err := deschedulerPolicyConfigMap(policy)
+	if err != nil {
+		t.Fatalf("Error creating %q CM with unlimited evictions: %v", deschedulerPolicyConfigMapObj.Name, err)
+	}
+	_, err = kubeClient.CoreV1().ConfigMaps(deschedulerPolicyConfigMapObj.Namespace).Update(ctx, deschedulerPolicyConfigMapObj, metav1.UpdateOptions{})
+	if err != nil {
+		t.Fatalf("Error updating %q CM: %v", deschedulerPolicyConfigMapObj.Name, err)
+	}
+}
+
+func createKubevirtClient() (generatedclient.Interface, error) {
+	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
+	loadingRules.DefaultClientConfig = &clientcmd.DefaultClientConfig
+	overrides := &clientcmd.ConfigOverrides{}
+	clientConfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, overrides)
+
+	config, err := clientConfig.ClientConfig()
+	if err != nil {
+		return nil, err
+	}
+	config.GroupVersion = &kvcorev1.StorageGroupVersion
+	config.APIPath = "/apis"
+	config.ContentType = runtime.ContentTypeJSON
+
+	return generatedclient.NewForConfig(config)
+}
+
+func TestLiveMigrationInBackground(t *testing.T) {
+	initPluginRegistry()
+
+	ctx := context.Background()
+
+	kubeClient, err := client.CreateClient(componentbaseconfig.ClientConnectionConfiguration{Kubeconfig: os.Getenv("KUBECONFIG")}, "")
+	if err != nil {
+		t.Fatalf("Error during kubernetes client creation with %v", err)
+	}
+
+	kvClient, err := createKubevirtClient()
+	if err != nil {
+		t.Fatalf("Error during kvClient creation with %v", err)
+	}
+
+	waitForKubevirtReady(t, ctx, kvClient)
+
+	// Delete all VMIs
+	defer func() {
+		for i := 1; i <= vmiCount; i++ {
+			vmi := virtualMachineInstance(i)
+			err := kvClient.KubevirtV1().VirtualMachineInstances("default").Delete(context.Background(), vmi.Name, metav1.DeleteOptions{})
+			if err != nil && !apierrors.IsNotFound(err) {
+				klog.Infof("Unable to delete vmi %v: %v", vmi.Name, err)
+			}
+		}
+		wait.PollUntilContextTimeout(ctx, 5*time.Second, 60*time.Second, true, func(ctx context.Context) (bool, error) {
+			podList, err := kubeClient.CoreV1().Pods("default").List(ctx, metav1.ListOptions{})
+			if err != nil {
+				return false, err
+			}
+			lPods := len(podList.Items)
+			if lPods > 0 {
+				klog.Infof("Waiting until all pods under default namespace are gone, %v remaining", lPods)
+				return false, nil
+			}
+			return true, nil
+		})
+	}()
+
+	// Create N vmis and wait for the corresponding vm pods to be ready and running
+	for i := 1; i <= vmiCount; i++ {
+		vmi := virtualMachineInstance(i)
+		_, err = kvClient.KubevirtV1().VirtualMachineInstances("default").Create(context.Background(), vmi, metav1.CreateOptions{})
+		if err != nil {
+			t.Fatalf("Unable to create KubeVirt vmi: %v\n", err)
+		}
+	}
+
+	// Wait until all VMIs have running pods
+	if err := wait.PollUntilContextTimeout(ctx, 5*time.Second, 300*time.Second, true, func(ctx context.Context) (bool, error) {
+		return allVMIsHaveRunningPods(t, ctx, kubeClient, kvClient)
+	}); err != nil {
+		t.Fatalf("Error waiting for all vmi active pods to be running: %v", err)
+	}
+
+	usedRunningPodNames := make(map[string]struct{})
+	// vmiCount number of names is expected
+	names := kVirtRunningPodNames(t, ctx, kubeClient)
+	klog.Infof("vmi pods: %#v\n", names)
+	if len(names) != vmiCount {
+		t.Fatalf("Expected %v vmi pods, got %v instead", vmiCount, len(names))
+	}
+	for _, name := range names {
+		usedRunningPodNames[name] = struct{}{}
+	}
+
+	policy := podLifeTimePolicy()
+	// Allow only a single eviction simultaneously
+	policy.MaxNoOfPodsToEvictPerNamespace = utilptr.To[uint](1)
+	// Deploy the descheduler with the configured policy
+	deschedulerPolicyConfigMapObj, err := deschedulerPolicyConfigMap(policy)
+	if err != nil {
+		t.Fatalf("Error creating %q CM: %v", deschedulerPolicyConfigMapObj.Name, err)
+	}
+	klog.Infof("Creating %q policy CM with RemovePodsHavingTooManyRestarts configured...", deschedulerPolicyConfigMapObj.Name)
+	_, err = kubeClient.CoreV1().ConfigMaps(deschedulerPolicyConfigMapObj.Namespace).Create(ctx, deschedulerPolicyConfigMapObj, metav1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating %q CM: %v", deschedulerPolicyConfigMapObj.Name, err)
+	}
+	defer func() {
+		klog.Infof("Deleting %q CM...", deschedulerPolicyConfigMapObj.Name)
+		err = kubeClient.CoreV1().ConfigMaps(deschedulerPolicyConfigMapObj.Namespace).Delete(ctx, deschedulerPolicyConfigMapObj.Name, metav1.DeleteOptions{})
+		if err != nil {
+			t.Fatalf("Unable to delete %q CM: %v", deschedulerPolicyConfigMapObj.Name, err)
+		}
+	}()
+
+	deschedulerDeploymentObj := deschedulerDeployment("kube-system")
+	// Set the descheduling interval to 10s
+	deschedulerDeploymentObj.Spec.Template.Spec.Containers[0].Args = []string{"--policy-config-file", "/policy-dir/policy.yaml", "--descheduling-interval", "10s", "--v", "4", "--feature-gates", "EvictionsInBackground=true"}
+
+	deschedulerPodName := ""
+	defer func() {
+		if deschedulerPodName != "" {
+			printPodLogs(ctx, t, kubeClient, deschedulerPodName)
+		}
+
+		klog.Infof("Deleting %q deployment...", deschedulerDeploymentObj.Name)
+		err = kubeClient.AppsV1().Deployments(deschedulerDeploymentObj.Namespace).Delete(ctx, deschedulerDeploymentObj.Name, metav1.DeleteOptions{})
+		if err != nil {
+			if apierrors.IsNotFound(err) {
+				return
+			}
+			t.Fatalf("Unable to delete %q deployment: %v", deschedulerDeploymentObj.Name, err)
+		}
+		waitForPodsToDisappear(ctx, t, kubeClient, deschedulerDeploymentObj.Labels, deschedulerDeploymentObj.Namespace)
+	}()
+
+	deschedulerPodName = createAndWaitForDeschedulerRunning(t, ctx, kubeClient, deschedulerDeploymentObj)
+
+	observeLiveMigration(t, ctx, kubeClient, usedRunningPodNames)
+
+	printPodLogs(ctx, t, kubeClient, deschedulerPodName)
+
+	klog.Infof("Deleting the current descheduler pod")
+	err = kubeClient.AppsV1().Deployments(deschedulerDeploymentObj.Namespace).Delete(ctx, deschedulerDeploymentObj.Name, metav1.DeleteOptions{})
+	if err != nil {
+		t.Fatalf("Error deleting %q deployment: %v", deschedulerDeploymentObj.Name, err)
+	}
+
+	remainingPods := make(map[string]struct{})
+	for _, name := range kVirtRunningPodNames(t, ctx, kubeClient) {
+		remainingPods[name] = struct{}{}
+	}
+
+	klog.Infof("Configuring the descheduler policy %v for PodLifetime with no limits", deschedulerPolicyConfigMapObj.Name)
+	policy.MaxNoOfPodsToEvictPerNamespace = nil
+	updateDeschedulerPolicy(t, ctx, kubeClient, policy)
+
+	deschedulerDeploymentObj = deschedulerDeployment("kube-system")
+	deschedulerDeploymentObj.Spec.Template.Spec.Containers[0].Args = []string{"--policy-config-file", "/policy-dir/policy.yaml", "--descheduling-interval", "100m", "--v", "4", "--feature-gates", "EvictionsInBackground=true"}
+	deschedulerPodName = createAndWaitForDeschedulerRunning(t, ctx, kubeClient, deschedulerDeploymentObj)
+
+	klog.Infof("Waiting until all pods are evicted (no limit set)")
+	if err := wait.PollUntilContextTimeout(ctx, 5*time.Second, 120*time.Second, true, func(ctx context.Context) (bool, error) {
+		names := kVirtRunningPodNames(t, ctx, kubeClient)
+		for _, name := range names {
+			if _, exists := remainingPods[name]; exists {
+				klog.Infof("Waiting for %v to disappear", name)
+				return false, nil
+			}
+		}
+		lNames := len(names)
+		if lNames != vmiCount {
+			klog.Infof("Waiting for the number of newly running vmi pods to be %v, got %v instead", vmiCount, lNames)
+			return false, nil
+		}
+		klog.Infof("The number of newly running vmi pods is %v as expected", vmiCount)
+		return true, nil
+	}); err != nil {
+		t.Fatalf("Error waiting for %v new vmi active pods to be running: %v", vmiCount, err)
+	}
+}

test/e2e/e2e_test.go

@@ -40,6 +40,7 @@ import (
 	clientset "k8s.io/client-go/kubernetes"
 	listersv1 "k8s.io/client-go/listers/core/v1"
 	componentbaseconfig "k8s.io/component-base/config"
+	"k8s.io/component-base/featuregate"
 	"k8s.io/klog/v2"
 	utilptr "k8s.io/utils/ptr"
 	"sigs.k8s.io/yaml"
@@ -54,6 +55,7 @@ import (
 	eutils "sigs.k8s.io/descheduler/pkg/descheduler/evictions/utils"
 	nodeutil "sigs.k8s.io/descheduler/pkg/descheduler/node"
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
+	"sigs.k8s.io/descheduler/pkg/features"
 	"sigs.k8s.io/descheduler/pkg/framework/pluginregistry"
 	"sigs.k8s.io/descheduler/pkg/framework/plugins/defaultevictor"
 	"sigs.k8s.io/descheduler/pkg/framework/plugins/nodeutilization"
@@ -68,6 +70,14 @@ func isClientRateLimiterError(err error) bool {
 	return strings.Contains(err.Error(), "client rate limiter")
 }
 
+func initFeatureGates() featuregate.FeatureGate {
+	featureGates := featuregate.NewFeatureGate()
+	featureGates.Add(map[featuregate.Feature]featuregate.FeatureSpec{
+		features.EvictionsInBackground: {Default: false, PreRelease: featuregate.Alpha},
+	})
+	return featureGates
+}
+
 func deschedulerPolicyConfigMap(policy *deschedulerapiv1alpha2.DeschedulerPolicy) (*v1.ConfigMap, error) {
 	cm := &v1.ConfigMap{
 		ObjectMeta: metav1.ObjectMeta{
@@ -1344,6 +1354,7 @@ func TestDeschedulingInterval(t *testing.T) {
 		t.Fatalf("Unable to initialize server: %v", err)
 	}
 	s.Client = clientSet
+	s.DefaultFeatureGates = initFeatureGates()
 
 	deschedulerPolicy := &deschedulerapi.DeschedulerPolicy{}
 

test/e2e/e2e_toomanyrestarts_test.go

@@ -148,6 +148,7 @@ func TestTooManyRestarts(t *testing.T) {
 			}
 			rs.Client = clientSet
 			rs.EventClient = clientSet
+			rs.DefaultFeatureGates = initFeatureGates()
 
 			preRunNames := sets.NewString(getCurrentPodNames(ctx, clientSet, testNamespace.Name, t)...)
 			// Deploy the descheduler with the configured policy

test/e2e/test_clientconnection_test.go

@@ -31,6 +31,7 @@ func TestClientConnectionConfiguration(t *testing.T) {
 		t.Fatalf("Unable to initialize server: %v", err)
 	}
 	s.Client = clientSet
+	s.DefaultFeatureGates = initFeatureGates()
 	evictionPolicyGroupVersion, err := eutils.SupportEviction(s.Client)
 	if err != nil || len(evictionPolicyGroupVersion) == 0 {
 		t.Errorf("Error when checking support for eviction: %v", err)