Fix PreferNominatedNode test

Once the node gets deleted, the nodelifecycle controller
is racing to update pod status and the pod deletion logic
is failing causing tests to flake. This commit moves
the testContext creation to within the test loop and deletes nodes,
namespace within the test loop. We don't explicitly call the node
deletion within the loop but the `testutils.CleanupTest(t, testCtx)`
call ensures that the namespace, nodes gets deleted.

test/integration/scheduler/preemption_test.go

@@ -1336,52 +1336,37 @@ func initTestPreferNominatedNode(t *testing.T, nsPrefix string, opts ...schedule
 // enabled.
 func TestPreferNominatedNode(t *testing.T) {
 	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.PreferNominatedNode, true)()
-	testCtx := initTestPreferNominatedNode(t, "perfer-nominated-node")
-	t.Cleanup(func() {
-		testutils.CleanupTest(t, testCtx)
-	})
-	cs := testCtx.ClientSet
-	defaultPodRes := &v1.ResourceRequirements{Requests: v1.ResourceList{
-		v1.ResourceCPU:    *resource.NewMilliQuantity(100, resource.DecimalSI),
-		v1.ResourceMemory: *resource.NewQuantity(100, resource.DecimalSI)},
-	}
+
 	defaultNodeRes := map[v1.ResourceName]string{
 		v1.ResourcePods:   "32",
 		v1.ResourceCPU:    "500m",
 		v1.ResourceMemory: "500",
 	}
-
-	type nodeConfig struct {
-		name string
-		res  map[v1.ResourceName]string
+	defaultPodRes := &v1.ResourceRequirements{Requests: v1.ResourceList{
+		v1.ResourceCPU:    *resource.NewMilliQuantity(100, resource.DecimalSI),
+		v1.ResourceMemory: *resource.NewQuantity(100, resource.DecimalSI)},
 	}
-
 	tests := []struct {
 		name         string
-		nodes        []*nodeConfig
+		nodeNames    []string
 		existingPods []*v1.Pod
 		pod          *v1.Pod
 		runnningNode string
 	}{
 		{
-			name: "nominated node released all resource, preemptor is scheduled to the nominated node",
-			nodes: []*nodeConfig{
-				{name: "node-1", res: defaultNodeRes},
-				{name: "node-2", res: defaultNodeRes},
-			},
+			name:      "nominated node released all resource, preemptor is scheduled to the nominated node",
+			nodeNames: []string{"node-1", "node-2"},
 			existingPods: []*v1.Pod{
 				initPausePod(&pausePodConfig{
 					Name:      "low-pod1",
-					Namespace: testCtx.NS.Name,
 					Priority:  &lowPriority,
 					NodeName:  "node-2",
 					Resources: defaultPodRes,
 				}),
 			},
 			pod: initPausePod(&pausePodConfig{
-				Name:      "preemptor-pod",
-				Namespace: testCtx.NS.Name,
-				Priority:  &highPriority,
+				Name:     "preemptor-pod",
+				Priority: &highPriority,
 				Resources: &v1.ResourceRequirements{Requests: v1.ResourceList{
 					v1.ResourceCPU:    *resource.NewMilliQuantity(500, resource.DecimalSI),
 					v1.ResourceMemory: *resource.NewQuantity(200, resource.DecimalSI)},
@@ -1390,24 +1375,19 @@ func TestPreferNominatedNode(t *testing.T) {
 			runnningNode: "node-1",
 		},
 		{
-			name: "nominated node cannot pass all the filters, preemptor should find a different node",
-			nodes: []*nodeConfig{
-				{name: "node-1", res: defaultNodeRes},
-				{name: "node-2", res: defaultNodeRes},
-			},
+			name:      "nominated node cannot pass all the filters, preemptor should find a different node",
+			nodeNames: []string{"node-1", "node-2"},
 			existingPods: []*v1.Pod{
 				initPausePod(&pausePodConfig{
-					Name:      "low-pod1",
-					Namespace: testCtx.NS.Name,
+					Name:      "low-pod",
 					Priority:  &lowPriority,
 					Resources: defaultPodRes,
 					NodeName:  "node-1",
 				}),
 			},
 			pod: initPausePod(&pausePodConfig{
-				Name:      "preemptor-pod",
-				Namespace: testCtx.NS.Name,
-				Priority:  &highPriority,
+				Name:     "preemptor-pod1",
+				Priority: &highPriority,
 				Resources: &v1.ResourceRequirements{Requests: v1.ResourceList{
 					v1.ResourceCPU:    *resource.NewMilliQuantity(500, resource.DecimalSI),
 					v1.ResourceMemory: *resource.NewQuantity(200, resource.DecimalSI)},
@@ -1419,22 +1399,31 @@ func TestPreferNominatedNode(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
+			testCtx := initTestPreferNominatedNode(t, "perfer-nominated-node")
+			t.Cleanup(func() {
+				testutils.CleanupTest(t, testCtx)
+			})
+			cs := testCtx.ClientSet
+			nsName := testCtx.NS.Name
 			var err error
 			var preemptor *v1.Pod
-			for _, nodeConf := range test.nodes {
-				_, err := createNode(cs, st.MakeNode().Name(nodeConf.name).Capacity(nodeConf.res).Obj())
+			for _, nodeName := range test.nodeNames {
+				_, err := createNode(cs, st.MakeNode().Name(nodeName).Capacity(defaultNodeRes).Obj())
 				if err != nil {
-					t.Fatalf("Error creating node %v: %v", nodeConf.name, err)
+					t.Fatalf("Error creating node %v: %v", nodeName, err)
 				}
 			}
+
 			pods := make([]*v1.Pod, len(test.existingPods))
 			// Create and run existingPods.
 			for i, p := range test.existingPods {
+				p.Namespace = nsName
 				pods[i], err = runPausePod(cs, p)
 				if err != nil {
 					t.Fatalf("Error running pause pod: %v", err)
 				}
 			}
+			test.pod.Namespace = nsName
 			preemptor, err = createPausePod(cs, test.pod)
 			if err != nil {
 				t.Errorf("Error while creating high priority pod: %v", err)
@@ -1456,10 +1445,6 @@ func TestPreferNominatedNode(t *testing.T) {
 			if preemptor.Spec.NodeName != test.runnningNode {
 				t.Errorf("Expect pod running on %v, got %v.", test.runnningNode, preemptor.Spec.NodeName)
 			}
-			pods = append(pods, preemptor)
-			// cleanup
-			defer testutils.CleanupPods(cs, t, pods)
-			cs.CoreV1().Nodes().DeleteCollection(context.TODO(), metav1.DeleteOptions{}, metav1.ListOptions{})
 		})
 	}
 }