Add DisruptionTarget condition when preempting for critical pod

Manually modified the commit to expect Failed phase instead of Succeeded.
This is expected in 1.26 as the code in preemption.go sets it to Failed.
In 1.27 the phase is determined by `getPhase` kubelet_pods.go based
on the completed containers.

pkg/kubelet/preemption/preemption.go

@@ -21,10 +21,13 @@ import (
 	"math"
 
 	v1 "k8s.io/api/core/v1"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/tools/record"
 	"k8s.io/klog/v2"
+	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
 	"k8s.io/kubernetes/pkg/api/v1/resource"
 	v1qos "k8s.io/kubernetes/pkg/apis/core/v1/helper/qos"
+	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/kubelet/events"
 	"k8s.io/kubernetes/pkg/kubelet/eviction"
 	"k8s.io/kubernetes/pkg/kubelet/lifecycle"
@@ -103,6 +106,14 @@ func (c *CriticalPodAdmissionHandler) evictPodsToFreeRequests(admitPod *v1.Pod,
 			status.Phase = v1.PodFailed
 			status.Reason = events.PreemptContainer
 			status.Message = message
+			if utilfeature.DefaultFeatureGate.Enabled(features.PodDisruptionConditions) {
+				podutil.UpdatePodCondition(status, &v1.PodCondition{
+					Type:    v1.DisruptionTarget,
+					Status:  v1.ConditionTrue,
+					Reason:  v1.PodReasonTerminationByKubelet,
+					Message: "Pod was preempted by Kubelet to accommodate a critical pod.",
+				})
+			}
 		})
 		if err != nil {
 			klog.ErrorS(err, "Failed to evict pod", "pod", klog.KObj(pod))

test/e2e_node/critical_pod_test.go

@@ -23,6 +23,7 @@ import (
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/klog/v2"
 	kubeapi "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/scheduling"
 	kubelettypes "k8s.io/kubernetes/pkg/kubelet/types"
@@ -87,6 +88,49 @@ var _ = SIGDescribe("CriticalPod [Serial] [Disruptive] [NodeFeature:CriticalPod]
 				}
 			}
 		})
+
+		ginkgo.It("should add DisruptionTarget condition to the preempted pod [NodeFeature:PodDisruptionConditions]", func() {
+			// because adminssion Priority enable, If the priority class is not found, the Pod is rejected.
+			node := getNodeName(f)
+			nonCriticalGuaranteed := getTestPod(false, guaranteedPodName, v1.ResourceRequirements{
+				Requests: v1.ResourceList{
+					v1.ResourceCPU:    resource.MustParse("100m"),
+					v1.ResourceMemory: resource.MustParse("100Mi"),
+				},
+				Limits: v1.ResourceList{
+					v1.ResourceCPU:    resource.MustParse("100m"),
+					v1.ResourceMemory: resource.MustParse("100Mi"),
+				},
+			}, node)
+
+			criticalPod := getTestPod(true, criticalPodName, v1.ResourceRequirements{
+				// request the entire resource capacity of the node, so that
+				// admitting this pod requires the other pod to be preempted
+				Requests: getNodeCPUAndMemoryCapacity(f),
+			}, node)
+			criticalPod.Namespace = kubeapi.NamespaceSystem
+
+			ginkgo.By(fmt.Sprintf("create the non-critical pod %q", klog.KObj(nonCriticalGuaranteed)))
+			e2epod.NewPodClient(f).CreateSync(nonCriticalGuaranteed)
+
+			ginkgo.By(fmt.Sprintf("create the critical pod %q", klog.KObj(criticalPod)))
+			e2epod.PodClientNS(f, kubeapi.NamespaceSystem).Create(criticalPod)
+
+			ginkgo.By(fmt.Sprintf("await for the critical pod %q to be ready", klog.KObj(criticalPod)))
+			err := e2epod.WaitForPodNameRunningInNamespace(f.ClientSet, criticalPod.Name, kubeapi.NamespaceSystem)
+			framework.ExpectNoError(err, "Failed to await for the pod to be running: %q", klog.KObj(criticalPod))
+
+			// Check that non-critical pods other than the besteffort have been evicted
+			updatedPodList, err := f.ClientSet.CoreV1().Pods(f.Namespace.Name).List(context.TODO(), metav1.ListOptions{})
+			framework.ExpectNoError(err)
+			for _, p := range updatedPodList.Items {
+				ginkgo.By(fmt.Sprintf("verify that the non-critical pod %q is preempted and has the DisruptionTarget condition", klog.KObj(&p)))
+				framework.ExpectEqual(p.Status.Phase, v1.PodFailed, fmt.Sprintf("pod: %v should be preempted with status: %#v", p.Name, p.Status))
+				if condition := e2epod.FindPodConditionByType(&p.Status, v1.DisruptionTarget); condition == nil {
+					framework.Failf("pod %q should have the condition: %q, pod status: %v", klog.KObj(&p), v1.DisruptionTarget, p.Status)
+				}
+			}
+		})
 		ginkgo.AfterEach(func() {
 			// Delete Pods
 			e2epod.NewPodClient(f).DeleteSync(guaranteedPodName, metav1.DeleteOptions{}, e2epod.DefaultPodDeletionTimeout)