From 818e180300a7903a05090ad1818ef80d43956aaf Mon Sep 17 00:00:00 2001
From: Michal Wozniak <mw219725@gmail.com>
Date: Tue, 8 Nov 2022 15:18:55 +0100
Subject: [PATCH] Add e2e test for adding DisruptionTarget condition to the
 preemption victim pod

---
 test/e2e/scheduling/predicates.go |  2 +
 test/e2e/scheduling/preemption.go | 73 +++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/test/e2e/scheduling/predicates.go b/test/e2e/scheduling/predicates.go
index 10204c9a552..7775b77596e 100644
--- a/test/e2e/scheduling/predicates.go
+++ b/test/e2e/scheduling/predicates.go
@@ -62,6 +62,7 @@ var workerNodes = sets.String{}
 type pausePodConfig struct {
 	Name                              string
 	Namespace                         string
+	Finalizers                        []string
 	Affinity                          *v1.Affinity
 	Annotations, Labels, NodeSelector map[string]string
 	Resources                         *v1.ResourceRequirements
@@ -897,6 +898,7 @@ func initPausePod(f *framework.Framework, conf pausePodConfig) *v1.Pod {
 			Labels:          map[string]string{},
 			Annotations:     map[string]string{},
 			OwnerReferences: conf.OwnerReferences,
+			Finalizers:      conf.Finalizers,
 		},
 		Spec: v1.PodSpec{
 			SecurityContext:           e2epod.GetRestrictedPodSecurityContext(),
diff --git a/test/e2e/scheduling/preemption.go b/test/e2e/scheduling/preemption.go
index 1c3e424fc5a..2c282214d8d 100644
--- a/test/e2e/scheduling/preemption.go
+++ b/test/e2e/scheduling/preemption.go
@@ -60,6 +60,10 @@ type priorityPair struct {
 
 var testExtendedResource = v1.ResourceName("scheduling.k8s.io/foo")
 
+const (
+	testFinalizer = "example.com/test-finalizer"
+)
+
 var _ = SIGDescribe("SchedulerPreemption [Serial]", func() {
 	var cs clientset.Interface
 	var nodeList *v1.NodeList
@@ -313,6 +317,75 @@ var _ = SIGDescribe("SchedulerPreemption [Serial]", func() {
 		}
 	})
 
+	// 1. Run a low priority pod with finalizer which consumes 1/1 of node resources
+	// 2. Schedule a higher priority pod which also consumes 1/1 of node resources
+	// 3. See if the pod with lower priority is preempted and has the pod disruption condition
+	// 4. Remove the finalizer so that the pod can be deleted by GC
+	ginkgo.It("validates pod disruption condition is added to the preempted pod", func() {
+		podRes := v1.ResourceList{testExtendedResource: resource.MustParse("1")}
+
+		ginkgo.By("Select a node to run the lower and higher priority pods")
+		framework.ExpectNotEqual(len(nodeList.Items), 0, "We need at least one node for the test to run")
+		node := nodeList.Items[0]
+		nodeCopy := node.DeepCopy()
+		nodeCopy.Status.Capacity[testExtendedResource] = resource.MustParse("1")
+		err := patchNode(cs, &node, nodeCopy)
+		framework.ExpectNoError(err)
+
+		// prepare node affinity to make sure both the lower and higher priority pods are scheduled on the same node
+		testNodeAffinity := v1.Affinity{
+			NodeAffinity: &v1.NodeAffinity{
+				RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
+					NodeSelectorTerms: []v1.NodeSelectorTerm{
+						{
+							MatchFields: []v1.NodeSelectorRequirement{
+								{Key: "metadata.name", Operator: v1.NodeSelectorOpIn, Values: []string{node.Name}},
+							},
+						},
+					},
+				},
+			},
+		}
+
+		ginkgo.By("Create a low priority pod that consumes 1/1 of node resources")
+		victimPod := createPausePod(f, pausePodConfig{
+			Name:              "victim-pod",
+			PriorityClassName: lowPriorityClassName,
+			Resources: &v1.ResourceRequirements{
+				Requests: podRes,
+				Limits:   podRes,
+			},
+			Finalizers: []string{testFinalizer},
+			Affinity:   &testNodeAffinity,
+		})
+		framework.Logf("Created pod: %v", victimPod.Name)
+
+		ginkgo.By("Wait for the victim pod to be scheduled")
+		framework.ExpectNoError(e2epod.WaitForPodRunningInNamespace(cs, victimPod))
+
+		// Remove the finalizer so that the victim pod can be GCed
+		defer e2epod.NewPodClient(f).RemoveFinalizer(victimPod.Name, testFinalizer)
+
+		ginkgo.By("Create a high priority pod to trigger preemption of the lower priority pod")
+		preemptorPod := createPausePod(f, pausePodConfig{
+			Name:              "preemptor-pod",
+			PriorityClassName: highPriorityClassName,
+			Resources: &v1.ResourceRequirements{
+				Requests: podRes,
+				Limits:   podRes,
+			},
+			Affinity: &testNodeAffinity,
+		})
+		framework.Logf("Created pod: %v", preemptorPod.Name)
+
+		ginkgo.By("Waiting for the victim pod to be terminating")
+		err = e2epod.WaitForPodTerminatingInNamespaceTimeout(f.ClientSet, victimPod.Name, victimPod.Namespace, framework.PodDeleteTimeout)
+		framework.ExpectNoError(err)
+
+		ginkgo.By("Verifying the pod has the pod disruption condition")
+		e2epod.VerifyPodHasConditionWithType(f, victimPod, v1.DisruptionTarget)
+	})
+
 	ginkgo.Context("PodTopologySpread Preemption", func() {
 		var nodeNames []string
 		var nodes []*v1.Node