k8s.io/kubernetes@v1.29.3/pkg/controller/deployment/sync_test.go

/*
Copyright 2016 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package deployment

import (
	"math"
	"testing"
	"time"

	apps "k8s.io/api/apps/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/intstr"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/client-go/informers"
	"k8s.io/client-go/kubernetes/fake"
	testclient "k8s.io/client-go/testing"
	"k8s.io/client-go/tools/record"
	"k8s.io/klog/v2/ktesting"
	"k8s.io/kubernetes/pkg/controller"
	deploymentutil "k8s.io/kubernetes/pkg/controller/deployment/util"
	"k8s.io/utils/ptr"
)

func TestScale(t *testing.T) {
	newTimestamp := metav1.Date(2016, 5, 20, 2, 0, 0, 0, time.UTC)
	oldTimestamp := metav1.Date(2016, 5, 20, 1, 0, 0, 0, time.UTC)
	olderTimestamp := metav1.Date(2016, 5, 20, 0, 0, 0, 0, time.UTC)

	var updatedTemplate = func(replicas int32) *apps.Deployment {
		d := newDeployment("foo", replicas, nil, nil, nil, map[string]string{"foo": "bar"})
		d.Spec.Template.Labels["another"] = "label"
		return d
	}

	tests := []struct {
		name          string
		deployment    *apps.Deployment
		oldDeployment *apps.Deployment

		newRS  *apps.ReplicaSet
		oldRSs []*apps.ReplicaSet

		expectedNew  *apps.ReplicaSet
		expectedOld  []*apps.ReplicaSet
		wasntUpdated map[string]bool

		desiredReplicasAnnotations map[string]int32
	}{
		{
			name:          "normal scaling event: 10 -> 12",
			deployment:    newDeployment("foo", 12, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 10, nil, nil, nil, nil),

			newRS:  rs("foo-v1", 10, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{},

			expectedNew: rs("foo-v1", 12, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{},
		},
		{
			name:          "normal scaling event: 10 -> 5",
			deployment:    newDeployment("foo", 5, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 10, nil, nil, nil, nil),

			newRS:  rs("foo-v1", 10, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{},

			expectedNew: rs("foo-v1", 5, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{},
		},
		{
			name:          "proportional scaling: 5 -> 10",
			deployment:    newDeployment("foo", 10, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 5, nil, nil, nil, nil),

			newRS:  rs("foo-v2", 2, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v1", 3, nil, oldTimestamp)},

			expectedNew: rs("foo-v2", 4, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v1", 6, nil, oldTimestamp)},
		},
		{
			name:          "proportional scaling: 5 -> 3",
			deployment:    newDeployment("foo", 3, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 5, nil, nil, nil, nil),

			newRS:  rs("foo-v2", 2, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v1", 3, nil, oldTimestamp)},

			expectedNew: rs("foo-v2", 1, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v1", 2, nil, oldTimestamp)},
		},
		{
			name:          "proportional scaling: 9 -> 4",
			deployment:    newDeployment("foo", 4, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 9, nil, nil, nil, nil),

			newRS:  rs("foo-v2", 8, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v1", 1, nil, oldTimestamp)},

			expectedNew: rs("foo-v2", 4, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v1", 0, nil, oldTimestamp)},
		},
		{
			name:          "proportional scaling: 7 -> 10",
			deployment:    newDeployment("foo", 10, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 7, nil, nil, nil, nil),

			newRS:  rs("foo-v3", 2, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 3, nil, oldTimestamp), rs("foo-v1", 2, nil, olderTimestamp)},

			expectedNew: rs("foo-v3", 3, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v2", 4, nil, oldTimestamp), rs("foo-v1", 3, nil, olderTimestamp)},
		},
		{
			name:          "proportional scaling: 13 -> 8",
			deployment:    newDeployment("foo", 8, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 13, nil, nil, nil, nil),

			newRS:  rs("foo-v3", 2, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 8, nil, oldTimestamp), rs("foo-v1", 3, nil, olderTimestamp)},

			expectedNew: rs("foo-v3", 1, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v2", 5, nil, oldTimestamp), rs("foo-v1", 2, nil, olderTimestamp)},
		},
		// Scales up the new replica set.
		{
			name:          "leftover distribution: 3 -> 4",
			deployment:    newDeployment("foo", 4, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 3, nil, nil, nil, nil),

			newRS:  rs("foo-v3", 1, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 1, nil, oldTimestamp), rs("foo-v1", 1, nil, olderTimestamp)},

			expectedNew: rs("foo-v3", 2, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v2", 1, nil, oldTimestamp), rs("foo-v1", 1, nil, olderTimestamp)},
		},
		// Scales down the older replica set.
		{
			name:          "leftover distribution: 3 -> 2",
			deployment:    newDeployment("foo", 2, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 3, nil, nil, nil, nil),

			newRS:  rs("foo-v3", 1, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 1, nil, oldTimestamp), rs("foo-v1", 1, nil, olderTimestamp)},

			expectedNew: rs("foo-v3", 1, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v2", 1, nil, oldTimestamp), rs("foo-v1", 0, nil, olderTimestamp)},
		},
		// Scales up the latest replica set first.
		{
			name:          "proportional scaling (no new rs): 4 -> 5",
			deployment:    newDeployment("foo", 5, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 4, nil, nil, nil, nil),

			newRS:  nil,
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 2, nil, oldTimestamp), rs("foo-v1", 2, nil, olderTimestamp)},

			expectedNew: nil,
			expectedOld: []*apps.ReplicaSet{rs("foo-v2", 3, nil, oldTimestamp), rs("foo-v1", 2, nil, olderTimestamp)},
		},
		// Scales down to zero
		{
			name:          "proportional scaling: 6 -> 0",
			deployment:    newDeployment("foo", 0, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 6, nil, nil, nil, nil),

			newRS:  rs("foo-v3", 3, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 2, nil, oldTimestamp), rs("foo-v1", 1, nil, olderTimestamp)},

			expectedNew: rs("foo-v3", 0, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v2", 0, nil, oldTimestamp), rs("foo-v1", 0, nil, olderTimestamp)},
		},
		// Scales up from zero
		{
			name:          "proportional scaling: 0 -> 6",
			deployment:    newDeployment("foo", 6, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 6, nil, nil, nil, nil),

			newRS:  rs("foo-v3", 0, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 0, nil, oldTimestamp), rs("foo-v1", 0, nil, olderTimestamp)},

			expectedNew:  rs("foo-v3", 6, nil, newTimestamp),
			expectedOld:  []*apps.ReplicaSet{rs("foo-v2", 0, nil, oldTimestamp), rs("foo-v1", 0, nil, olderTimestamp)},
			wasntUpdated: map[string]bool{"foo-v2": true, "foo-v1": true},
		},
		// Scenario: deployment.spec.replicas == 3 ( foo-v1.spec.replicas == foo-v2.spec.replicas == foo-v3.spec.replicas == 1 )
		// Deployment is scaled to 5. foo-v3.spec.replicas and foo-v2.spec.replicas should increment by 1 but foo-v2 fails to
		// update.
		{
			name:          "failed rs update",
			deployment:    newDeployment("foo", 5, nil, nil, nil, nil),
			oldDeployment: newDeployment("foo", 5, nil, nil, nil, nil),

			newRS:  rs("foo-v3", 2, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 1, nil, oldTimestamp), rs("foo-v1", 1, nil, olderTimestamp)},

			expectedNew:  rs("foo-v3", 2, nil, newTimestamp),
			expectedOld:  []*apps.ReplicaSet{rs("foo-v2", 2, nil, oldTimestamp), rs("foo-v1", 1, nil, olderTimestamp)},
			wasntUpdated: map[string]bool{"foo-v3": true, "foo-v1": true},

			desiredReplicasAnnotations: map[string]int32{"foo-v2": int32(3)},
		},
		{
			name:          "deployment with surge pods",
			deployment:    newDeployment("foo", 20, nil, ptr.To(intstr.FromInt32(2)), nil, nil),
			oldDeployment: newDeployment("foo", 10, nil, ptr.To(intstr.FromInt32(2)), nil, nil),

			newRS:  rs("foo-v2", 6, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v1", 6, nil, oldTimestamp)},

			expectedNew: rs("foo-v2", 11, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v1", 11, nil, oldTimestamp)},
		},
		{
			name:          "change both surge and size",
			deployment:    newDeployment("foo", 50, nil, ptr.To(intstr.FromInt32(6)), nil, nil),
			oldDeployment: newDeployment("foo", 10, nil, ptr.To(intstr.FromInt32(3)), nil, nil),

			newRS:  rs("foo-v2", 5, nil, newTimestamp),
			oldRSs: []*apps.ReplicaSet{rs("foo-v1", 8, nil, oldTimestamp)},

			expectedNew: rs("foo-v2", 22, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v1", 34, nil, oldTimestamp)},
		},
		{
			name:          "change both size and template",
			deployment:    updatedTemplate(14),
			oldDeployment: newDeployment("foo", 10, nil, nil, nil, map[string]string{"foo": "bar"}),

			newRS:  nil,
			oldRSs: []*apps.ReplicaSet{rs("foo-v2", 7, nil, newTimestamp), rs("foo-v1", 3, nil, oldTimestamp)},

			expectedNew: nil,
			expectedOld: []*apps.ReplicaSet{rs("foo-v2", 10, nil, newTimestamp), rs("foo-v1", 4, nil, oldTimestamp)},
		},
		{
			name:          "saturated but broken new replica set does not affect old pods",
			deployment:    newDeployment("foo", 2, nil, ptr.To(intstr.FromInt32(1)), ptr.To(intstr.FromInt32(1)), nil),
			oldDeployment: newDeployment("foo", 2, nil, ptr.To(intstr.FromInt32(1)), ptr.To(intstr.FromInt32(1)), nil),

			newRS: func() *apps.ReplicaSet {
				rs := rs("foo-v2", 2, nil, newTimestamp)
				rs.Status.AvailableReplicas = 0
				return rs
			}(),
			oldRSs: []*apps.ReplicaSet{rs("foo-v1", 1, nil, oldTimestamp)},

			expectedNew: rs("foo-v2", 2, nil, newTimestamp),
			expectedOld: []*apps.ReplicaSet{rs("foo-v1", 1, nil, oldTimestamp)},
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			_ = olderTimestamp
			t.Log(test.name)
			fake := fake.Clientset{}
			dc := &DeploymentController{
				client:        &fake,
				eventRecorder: &record.FakeRecorder{},
			}

			if test.newRS != nil {
				desiredReplicas := *(test.oldDeployment.Spec.Replicas)
				if desired, ok := test.desiredReplicasAnnotations[test.newRS.Name]; ok {
					desiredReplicas = desired
				}
				deploymentutil.SetReplicasAnnotations(test.newRS, desiredReplicas, desiredReplicas+deploymentutil.MaxSurge(*test.oldDeployment))
			}
			for i := range test.oldRSs {
				rs := test.oldRSs[i]
				if rs == nil {
					continue
				}
				desiredReplicas := *(test.oldDeployment.Spec.Replicas)
				if desired, ok := test.desiredReplicasAnnotations[rs.Name]; ok {
					desiredReplicas = desired
				}
				deploymentutil.SetReplicasAnnotations(rs, desiredReplicas, desiredReplicas+deploymentutil.MaxSurge(*test.oldDeployment))
			}

			_, ctx := ktesting.NewTestContext(t)

			if err := dc.scale(ctx, test.deployment, test.newRS, test.oldRSs); err != nil {
				t.Errorf("%s: unexpected error: %v", test.name, err)
				return
			}

			// Construct the nameToSize map that will hold all the sizes we got our of tests
			// Skip updating the map if the replica set wasn't updated since there will be
			// no update action for it.
			nameToSize := make(map[string]int32)
			if test.newRS != nil {
				nameToSize[test.newRS.Name] = *(test.newRS.Spec.Replicas)
			}
			for i := range test.oldRSs {
				rs := test.oldRSs[i]
				nameToSize[rs.Name] = *(rs.Spec.Replicas)
			}
			// Get all the UPDATE actions and update nameToSize with all the updated sizes.
			for _, action := range fake.Actions() {
				rs := action.(testclient.UpdateAction).GetObject().(*apps.ReplicaSet)
				if !test.wasntUpdated[rs.Name] {
					nameToSize[rs.Name] = *(rs.Spec.Replicas)
				}
			}

			if test.expectedNew != nil && test.newRS != nil && *(test.expectedNew.Spec.Replicas) != nameToSize[test.newRS.Name] {
				t.Errorf("%s: expected new replicas: %d, got: %d", test.name, *(test.expectedNew.Spec.Replicas), nameToSize[test.newRS.Name])
				return
			}
			if len(test.expectedOld) != len(test.oldRSs) {
				t.Errorf("%s: expected %d old replica sets, got %d", test.name, len(test.expectedOld), len(test.oldRSs))
				return
			}
			for n := range test.oldRSs {
				rs := test.oldRSs[n]
				expected := test.expectedOld[n]
				if *(expected.Spec.Replicas) != nameToSize[rs.Name] {
					t.Errorf("%s: expected old (%s) replicas: %d, got: %d", test.name, rs.Name, *(expected.Spec.Replicas), nameToSize[rs.Name])
				}
			}
		})
	}
}

func TestDeploymentController_cleanupDeployment(t *testing.T) {
	selector := map[string]string{"foo": "bar"}
	alreadyDeleted := newRSWithStatus("foo-1", 0, 0, selector)
	now := metav1.Now()
	alreadyDeleted.DeletionTimestamp = &now

	tests := []struct {
		oldRSs               []*apps.ReplicaSet
		revisionHistoryLimit int32
		expectedDeletions    int
	}{
		{
			oldRSs: []*apps.ReplicaSet{
				newRSWithStatus("foo-1", 0, 0, selector),
				newRSWithStatus("foo-2", 0, 0, selector),
				newRSWithStatus("foo-3", 0, 0, selector),
			},
			revisionHistoryLimit: 1,
			expectedDeletions:    2,
		},
		{
			// Only delete the replica set with Spec.Replicas = Status.Replicas = 0.
			oldRSs: []*apps.ReplicaSet{
				newRSWithStatus("foo-1", 0, 0, selector),
				newRSWithStatus("foo-2", 0, 1, selector),
				newRSWithStatus("foo-3", 1, 0, selector),
				newRSWithStatus("foo-4", 1, 1, selector),
			},
			revisionHistoryLimit: 0,
			expectedDeletions:    1,
		},

		{
			oldRSs: []*apps.ReplicaSet{
				newRSWithStatus("foo-1", 0, 0, selector),
				newRSWithStatus("foo-2", 0, 0, selector),
			},
			revisionHistoryLimit: 0,
			expectedDeletions:    2,
		},
		{
			oldRSs: []*apps.ReplicaSet{
				newRSWithStatus("foo-1", 1, 1, selector),
				newRSWithStatus("foo-2", 1, 1, selector),
			},
			revisionHistoryLimit: 0,
			expectedDeletions:    0,
		},
		{
			oldRSs: []*apps.ReplicaSet{
				alreadyDeleted,
			},
			revisionHistoryLimit: 0,
			expectedDeletions:    0,
		},
		{
			// with unlimited revisionHistoryLimit
			oldRSs: []*apps.ReplicaSet{
				newRSWithStatus("foo-1", 0, 0, selector),
				newRSWithStatus("foo-2", 0, 0, selector),
				newRSWithStatus("foo-3", 0, 0, selector),
			},
			revisionHistoryLimit: math.MaxInt32,
			expectedDeletions:    0,
		},
	}

	for i := range tests {
		test := tests[i]
		t.Logf("scenario %d", i)

		_, ctx := ktesting.NewTestContext(t)

		fake := &fake.Clientset{}
		informers := informers.NewSharedInformerFactory(fake, controller.NoResyncPeriodFunc())
		controller, err := NewDeploymentController(ctx, informers.Apps().V1().Deployments(), informers.Apps().V1().ReplicaSets(), informers.Core().V1().Pods(), fake)
		if err != nil {
			t.Fatalf("error creating Deployment controller: %v", err)
		}

		controller.eventRecorder = &record.FakeRecorder{}
		controller.dListerSynced = alwaysReady
		controller.rsListerSynced = alwaysReady
		controller.podListerSynced = alwaysReady
		for _, rs := range test.oldRSs {
			informers.Apps().V1().ReplicaSets().Informer().GetIndexer().Add(rs)
		}

		stopCh := make(chan struct{})
		defer close(stopCh)
		informers.Start(stopCh)
		informers.WaitForCacheSync(stopCh)

		t.Logf(" &test.revisionHistoryLimit: %d", test.revisionHistoryLimit)
		d := newDeployment("foo", 1, &test.revisionHistoryLimit, nil, nil, map[string]string{"foo": "bar"})
		controller.cleanupDeployment(ctx, test.oldRSs, d)

		gotDeletions := 0
		for _, action := range fake.Actions() {
			if action.GetVerb() == "delete" {
				gotDeletions++
			}
		}
		if gotDeletions != test.expectedDeletions {
			t.Errorf("expect %v old replica sets been deleted, but got %v", test.expectedDeletions, gotDeletions)
			continue
		}
	}
}

func TestDeploymentController_cleanupDeploymentOrder(t *testing.T) {
	selector := map[string]string{"foo": "bar"}
	now := metav1.Now()
	duration := time.Minute

	newRSWithRevisionAndCreationTimestamp := func(name string, replicas int32, selector map[string]string, timestamp time.Time, revision string) *apps.ReplicaSet {
		rs := rs(name, replicas, selector, metav1.NewTime(timestamp))
		if revision != "" {
			rs.Annotations = map[string]string{
				deploymentutil.RevisionAnnotation: revision,
			}
		}
		rs.Status = apps.ReplicaSetStatus{
			Replicas: int32(replicas),
		}
		return rs
	}

	// for all test cases, creationTimestamp order keeps as: rs1 < rs2 < rs3 < r4
	tests := []struct {
		oldRSs               []*apps.ReplicaSet
		revisionHistoryLimit int32
		expectedDeletedRSs   sets.String
	}{
		{
			// revision order: rs1 < rs2, delete rs1
			oldRSs: []*apps.ReplicaSet{
				newRSWithRevisionAndCreationTimestamp("foo-1", 0, selector, now.Add(-1*duration), "1"),
				newRSWithRevisionAndCreationTimestamp("foo-2", 0, selector, now.Time, "2"),
			},
			revisionHistoryLimit: 1,
			expectedDeletedRSs:   sets.NewString("foo-1"),
		},
		{
			// revision order: rs2 < rs1, delete rs2
			oldRSs: []*apps.ReplicaSet{
				newRSWithRevisionAndCreationTimestamp("foo-1", 0, selector, now.Add(-1*duration), "2"),
				newRSWithRevisionAndCreationTimestamp("foo-2", 0, selector, now.Time, "1"),
			},
			revisionHistoryLimit: 1,
			expectedDeletedRSs:   sets.NewString("foo-2"),
		},
		{
			// rs1 has revision but rs2 doesn't have revision, delete rs2
			oldRSs: []*apps.ReplicaSet{
				newRSWithRevisionAndCreationTimestamp("foo-1", 0, selector, now.Add(-1*duration), "1"),
				newRSWithRevisionAndCreationTimestamp("foo-2", 0, selector, now.Time, ""),
			},
			revisionHistoryLimit: 1,
			expectedDeletedRSs:   sets.NewString("foo-2"),
		},
		{
			// rs1 doesn't have revision while rs2 has revision, delete rs1
			oldRSs: []*apps.ReplicaSet{
				newRSWithRevisionAndCreationTimestamp("foo-1", 0, selector, now.Add(-1*duration), ""),
				newRSWithRevisionAndCreationTimestamp("foo-2", 0, selector, now.Time, "2"),
			},
			revisionHistoryLimit: 1,
			expectedDeletedRSs:   sets.NewString("foo-1"),
		},
		{
			// revision order: rs1 < rs2 < r3, but rs1 has replicas, delete rs2
			oldRSs: []*apps.ReplicaSet{
				newRSWithRevisionAndCreationTimestamp("foo-1", 1, selector, now.Add(-1*duration), "1"),
				newRSWithRevisionAndCreationTimestamp("foo-2", 0, selector, now.Time, "2"),
				newRSWithRevisionAndCreationTimestamp("foo-3", 0, selector, now.Add(duration), "3"),
			},
			revisionHistoryLimit: 1,
			expectedDeletedRSs:   sets.NewString("foo-2"),
		},
		{
			// revision order: rs1 < rs2 < r3, both rs1 && rs2 have replicas, don't delete
			oldRSs: []*apps.ReplicaSet{
				newRSWithRevisionAndCreationTimestamp("foo-1", 1, selector, now.Add(-1*duration), "1"),
				newRSWithRevisionAndCreationTimestamp("foo-2", 1, selector, now.Time, "2"),
				newRSWithRevisionAndCreationTimestamp("foo-3", 0, selector, now.Add(duration), "3"),
			},
			revisionHistoryLimit: 1,
			expectedDeletedRSs:   sets.NewString(),
		},
		{
			// revision order: rs2 < rs4 < rs1 < rs3, delete rs2 && rs4
			oldRSs: []*apps.ReplicaSet{
				newRSWithRevisionAndCreationTimestamp("foo-1", 0, selector, now.Add(-1*duration), "3"),
				newRSWithRevisionAndCreationTimestamp("foo-2", 0, selector, now.Time, "1"),
				newRSWithRevisionAndCreationTimestamp("foo-3", 0, selector, now.Add(duration), "4"),
				newRSWithRevisionAndCreationTimestamp("foo-4", 0, selector, now.Add(2*duration), "2"),
			},
			revisionHistoryLimit: 2,
			expectedDeletedRSs:   sets.NewString("foo-2", "foo-4"),
		},
	}

	for i := range tests {
		test := tests[i]
		t.Logf("scenario %d", i)

		_, ctx := ktesting.NewTestContext(t)

		fake := &fake.Clientset{}
		informers := informers.NewSharedInformerFactory(fake, controller.NoResyncPeriodFunc())
		controller, err := NewDeploymentController(ctx, informers.Apps().V1().Deployments(), informers.Apps().V1().ReplicaSets(), informers.Core().V1().Pods(), fake)
		if err != nil {
			t.Fatalf("error creating Deployment controller: %v", err)
		}

		controller.eventRecorder = &record.FakeRecorder{}
		controller.dListerSynced = alwaysReady
		controller.rsListerSynced = alwaysReady
		controller.podListerSynced = alwaysReady
		for _, rs := range test.oldRSs {
			informers.Apps().V1().ReplicaSets().Informer().GetIndexer().Add(rs)
		}

		stopCh := make(chan struct{})
		defer close(stopCh)
		informers.Start(stopCh)

		d := newDeployment("foo", 1, &test.revisionHistoryLimit, nil, nil, map[string]string{"foo": "bar"})
		controller.cleanupDeployment(ctx, test.oldRSs, d)

		deletedRSs := sets.String{}
		for _, action := range fake.Actions() {
			deleteAction, ok := action.(testclient.DeleteActionImpl)
			if !ok {
				t.Logf("Found not-delete action with verb %v. Ignoring.", action.GetVerb())
				continue
			}

			if deleteAction.GetResource().Resource != "replicasets" {
				continue
			}

			deletedRSs.Insert(deleteAction.GetName())
		}
		t.Logf("&test.revisionHistoryLimit: %d, &test.deletedReplicaSets: %v", test.revisionHistoryLimit, deletedRSs)

		if !test.expectedDeletedRSs.Equal(deletedRSs) {
			t.Errorf("expect to delete old replica sets %v, but got %v", test.expectedDeletedRSs, deletedRSs)
			continue
		}
	}
}