Introduction of a pod condition type indicating disruption. Its reason field indicates the reason:

- PreemptionByKubeScheduler (Pod preempted by kube-scheduler)
- DeletionByTaintManager (Pod deleted by taint manager due to NoExecute taint)
- EvictionByEvictionAPI (Pod evicted by Eviction API)
- DeletionByPodGC (an orphaned Pod deleted by PodGC)PreemptedByScheduler (Pod preempted by kube-scheduler)

test/integration/scheduler/preemption/preemption_test.go

@@ -33,13 +33,16 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/intstr"
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/informers"
 	clientset "k8s.io/client-go/kubernetes"
 	restclient "k8s.io/client-go/rest"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
 	"k8s.io/klog/v2"
 	configv1 "k8s.io/kube-scheduler/config/v1"
 	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
 	"k8s.io/kubernetes/pkg/apis/scheduling"
+	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/scheduler"
 	configtesting "k8s.io/kubernetes/pkg/scheduler/apis/config/testing"
 	"k8s.io/kubernetes/pkg/scheduler/framework"
@@ -186,13 +189,40 @@ func TestPreemption(t *testing.T) {
 
 	maxTokens := 1000
 	tests := []struct {
-		name                string
-		existingPods        []*v1.Pod
-		pod                 *v1.Pod
-		initTokens          int
-		unresolvable        bool
-		preemptedPodIndexes map[int]struct{}
+		name                          string
+		existingPods                  []*v1.Pod
+		pod                           *v1.Pod
+		initTokens                    int
+		unresolvable                  bool
+		preemptedPodIndexes           map[int]struct{}
+		enablePodDisruptionConditions bool
 	}{
+		{
+			name:       "basic pod preemption with PodDisruptionConditions enabled",
+			initTokens: maxTokens,
+			existingPods: []*v1.Pod{
+				initPausePod(&testutils.PausePodConfig{
+					Name:      "victim-pod",
+					Namespace: testCtx.NS.Name,
+					Priority:  &lowPriority,
+					Resources: &v1.ResourceRequirements{Requests: v1.ResourceList{
+						v1.ResourceCPU:    *resource.NewMilliQuantity(400, resource.DecimalSI),
+						v1.ResourceMemory: *resource.NewQuantity(200, resource.DecimalSI)},
+					},
+				}),
+			},
+			pod: initPausePod(&testutils.PausePodConfig{
+				Name:      "preemptor-pod",
+				Namespace: testCtx.NS.Name,
+				Priority:  &highPriority,
+				Resources: &v1.ResourceRequirements{Requests: v1.ResourceList{
+					v1.ResourceCPU:    *resource.NewMilliQuantity(300, resource.DecimalSI),
+					v1.ResourceMemory: *resource.NewQuantity(200, resource.DecimalSI)},
+				},
+			}),
+			preemptedPodIndexes:           map[int]struct{}{0: {}},
+			enablePodDisruptionConditions: true,
+		},
 		{
 			name:       "basic pod preemption",
 			initTokens: maxTokens,
@@ -412,6 +442,7 @@ func TestPreemption(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
+			defer featuregatetesting.SetFeatureGateDuringTest(t, feature.DefaultFeatureGate, features.PodDisruptionConditions, test.enablePodDisruptionConditions)()
 			filter.Tokens = test.initTokens
 			filter.Unresolvable = test.unresolvable
 			pods := make([]*v1.Pod, len(test.existingPods))
@@ -433,6 +464,16 @@ func TestPreemption(t *testing.T) {
 					if err = wait.Poll(time.Second, wait.ForeverTestTimeout, podIsGettingEvicted(cs, p.Namespace, p.Name)); err != nil {
 						t.Errorf("Pod %v/%v is not getting evicted.", p.Namespace, p.Name)
 					}
+					pod, err := cs.CoreV1().Pods(p.Namespace).Get(testCtx.Ctx, p.Name, metav1.GetOptions{})
+					if err != nil {
+						t.Errorf("Error %v when getting the updated status for pod %v/%v ", err, p.Namespace, p.Name)
+					}
+					_, cond := podutil.GetPodCondition(&pod.Status, v1.AlphaNoCompatGuaranteeDisruptionTarget)
+					if test.enablePodDisruptionConditions == true && cond == nil {
+						t.Errorf("Pod %q does not have the expected condition: %q", klog.KObj(pod), v1.AlphaNoCompatGuaranteeDisruptionTarget)
+					} else if test.enablePodDisruptionConditions == false && cond != nil {
+						t.Errorf("Pod %q has an unexpected condition: %q", klog.KObj(pod), v1.AlphaNoCompatGuaranteeDisruptionTarget)
+					}
 				} else {
 					if p.DeletionTimestamp != nil {
 						t.Errorf("Didn't expect pod %v to get preempted.", p.Name)