Addressed review comment from Madhav about OwnerReferences.

This commit addresses the review comment gardener#539 (comment)

api/v1alpha1/types_etcd.go

@@ -460,8 +460,8 @@ func (e *Etcd) GetDefaultLabels() map[string]string {
 }
 
 // GetAsOwnerReference returns an OwnerReference object that represents the current Etcd instance.
-func (e *Etcd) GetAsOwnerReference() metav1.OwnerReference {
-	return metav1.OwnerReference{
+func (e *Etcd) GetAsOwnerReference() *metav1.OwnerReference {
+	return &metav1.OwnerReference{
 		APIVersion:         GroupVersion.String(),
 		Kind:               "Etcd",
 		Name:               e.Name,

api/v1alpha1/types_etcd_test.go

@@ -129,7 +129,6 @@ var _ = Describe("Etcd", func() {
 
 	Context("GetAsOwnerReference", func() {
 		It("should return an OwnerReference object that represents the current Etcd instance", func() {
-
 			expected := metav1.OwnerReference{
 				APIVersion:         GroupVersion.String(),
 				Kind:               "Etcd",
@@ -138,7 +137,9 @@ var _ = Describe("Etcd", func() {
 				Controller:         pointer.Bool(true),
 				BlockOwnerDeletion: pointer.Bool(true),
 			}
-			Expect(created.GetAsOwnerReference()).To(Equal(expected))
+			actual := created.GetAsOwnerReference()
+			Expect(actual).NotTo(BeNil())
+			Expect(*created.GetAsOwnerReference()).To(Equal(expected))
 		})
 	})
 

pkg/component/etcd/configmap/configmap.go

@@ -165,7 +165,7 @@ func (c *component) syncConfigmap(ctx context.Context, cm *corev1.ConfigMap) err
 		cm.Name = c.values.Name
 		cm.Namespace = c.namespace
 		cm.Labels = c.values.Labels
-		cm.OwnerReferences = c.values.OwnerReferences
+		cm.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 		cm.Data = map[string]string{"etcd.conf.yaml": c.getEtcdConfigYaml()}
 		return nil
 	})

pkg/component/etcd/configmap/configmap_test.go

@@ -194,7 +194,7 @@ var _ = Describe("Configmap", func() {
 func checkConfigmap(cm *corev1.ConfigMap, values *Values, namespace string) {
 
 	Expect(cm.Name).To(Equal(values.Name))
-	Expect(cm.OwnerReferences).To(Equal(values.OwnerReferences))
+	Expect(cm.OwnerReferences).To(Equal([]metav1.OwnerReference{*values.OwnerReference}))
 	Expect(cm.Labels).To(Equal(values.Labels))
 	configYML := cm.Data[etcdConfig]
 	config := map[string]interface{}{}

pkg/component/etcd/configmap/values.go

@@ -59,6 +59,6 @@ type Values struct {
 	ConfigMapChecksum string
 	// Labels is the labels of deployed configmap
 	Labels map[string]string
-	// OwnerReferences are the OwnerReferences of the Configmap.
-	OwnerReferences []metav1.OwnerReference
+	// OwnerReference are the OwnerReference of the Configmap.
+	OwnerReference *metav1.OwnerReference
 }

pkg/component/etcd/configmap/values_helper.go

@@ -20,7 +20,6 @@ import (
 	"strings"
 
 	druidv1alpha1 "github.com/gardener/etcd-druid/api/v1alpha1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/utils/pointer"
 )
 
@@ -41,7 +40,7 @@ func GenerateValues(etcd *druidv1alpha1.Etcd) *Values {
 		ServerPort:              etcd.Spec.Etcd.ServerPort,
 		AutoCompactionMode:      etcd.Spec.Common.AutoCompactionMode,
 		AutoCompactionRetention: etcd.Spec.Common.AutoCompactionRetention,
-		OwnerReferences:         []metav1.OwnerReference{etcd.GetAsOwnerReference()},
+		OwnerReference:          etcd.GetAsOwnerReference(),
 		Labels:                  etcd.GetDefaultLabels(),
 	}
 	return values

pkg/component/etcd/lease/lease_member.go

@@ -23,6 +23,7 @@ import (
 	"github.com/gardener/gardener/pkg/controllerutils"
 	"github.com/gardener/gardener/pkg/utils/flow"
 	coordinationv1 "k8s.io/api/coordination/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
@@ -55,7 +56,7 @@ func (c *component) syncMemberLeases(ctx context.Context) error {
 				for k, v := range labels {
 					lease.Labels[k] = v
 				}
-				lease.OwnerReferences = c.values.OwnerReferences
+				lease.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 				return nil
 			})
 			return err

pkg/component/etcd/lease/lease_snapshot.go

@@ -20,6 +20,7 @@ import (
 	"github.com/gardener/gardener/pkg/controllerutils"
 
 	coordinationv1 "k8s.io/api/coordination/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
@@ -32,7 +33,7 @@ func (c *component) syncSnapshotLease(ctx context.Context, lease *coordinationv1
 		return c.deleteSnapshotLease(ctx, lease)
 	}
 	_, err := controllerutils.GetAndCreateOrMergePatch(ctx, c.client, lease, func() error {
-		lease.OwnerReferences = c.values.OwnerReferences
+		lease.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 		return nil
 	})
 	return err

pkg/component/etcd/lease/values.go

@@ -30,6 +30,6 @@ type Values struct {
 	Replicas int32
 	// Labels is the labels of deployed configmap
 	Labels map[string]string
-	// OwnerReferences are the OwnerReferences of the Configmap.
-	OwnerReferences []metav1.OwnerReference
+	// OwnerReference are the OwnerReference of the Configmap.
+	OwnerReference *metav1.OwnerReference
 }

pkg/component/etcd/lease/values_helper.go

@@ -16,7 +16,6 @@ package lease
 
 import (
 	druidv1alpha1 "github.com/gardener/etcd-druid/api/v1alpha1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 // GenerateValues generates `lease.Values` for the lease component
@@ -27,6 +26,6 @@ func GenerateValues(etcd *druidv1alpha1.Etcd) Values {
 		DeltaSnapshotLeaseName: etcd.GetDeltaSnapshotLeaseName(),
 		FullSnapshotLeaseName:  etcd.GetFullSnapshotLeaseName(),
 		Replicas:               etcd.Spec.Replicas,
-		OwnerReferences:        []metav1.OwnerReference{etcd.GetAsOwnerReference()},
+		OwnerReference:         etcd.GetAsOwnerReference(),
 	}
 }

pkg/component/etcd/poddisruptionbudget/poddisruptionbudget.go

@@ -90,7 +90,7 @@ func (c *component) syncPodDisruptionBudget(ctx context.Context, pdb client.Obje
 	case *policyv1.PodDisruptionBudget:
 		_, err := controllerutils.GetAndCreateOrMergePatch(ctx, c.client, pdb, func() error {
 			pdb.Labels = c.values.Labels
-			pdb.OwnerReferences = c.values.OwnerReferences
+			pdb.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 			pdb.Spec.MinAvailable = &intstr.IntOrString{
 				IntVal: c.values.MinAvailable,
 				Type:   intstr.Int,
@@ -105,7 +105,7 @@ func (c *component) syncPodDisruptionBudget(ctx context.Context, pdb client.Obje
 		_, err := controllerutils.GetAndCreateOrMergePatch(ctx, c.client, pdb, func() error {
 			pdb.Annotations = c.values.Annotations
 			pdb.Labels = c.values.Labels
-			pdb.OwnerReferences = c.values.OwnerReferences
+			pdb.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 			pdb.Spec.MinAvailable = &intstr.IntOrString{
 				IntVal: c.values.MinAvailable,
 				Type:   intstr.Int,

pkg/component/etcd/poddisruptionbudget/poddisruptionbudget_test.go

@@ -332,7 +332,7 @@ func checkV1PDB(pdb *policyv1.PodDisruptionBudget, values *Values, expectedNames
 func checkPDBMetadata(meta *metav1.ObjectMeta, values *Values, expectedNamespace string) {
 	Expect(meta.Name).To(Equal(values.Name))
 	Expect(meta.Namespace).To(Equal(expectedNamespace))
-	Expect(meta.OwnerReferences).To(Equal(values.OwnerReferences))
+	Expect(meta.OwnerReferences).To(Equal([]metav1.OwnerReference{*values.OwnerReference}))
 	Expect(meta.Labels).To(Equal(pdbLabels(values)))
 }
 

pkg/component/etcd/poddisruptionbudget/values.go

@@ -36,6 +36,6 @@ type Values struct {
 	Annotations map[string]string
 	// MinAvailable defined the minimum number of pods to be available at any point of time
 	MinAvailable int32
-	// OwnerReferences are the OwnerReferences of the PodDisruptionBudget.
-	OwnerReferences []metav1.OwnerReference
+	// OwnerReference are the OwnerReference of the PodDisruptionBudget.
+	OwnerReference *metav1.OwnerReference
 }

pkg/component/etcd/poddisruptionbudget/values_helper.go

@@ -34,6 +34,7 @@ func GenerateValues(etcd *druidv1alpha1.Etcd) Values {
 		SelectorLabels: etcd.GetDefaultLabels(),
 		Annotations:    annotations,
 		MinAvailable:   int32(CalculatePDBMinAvailable(etcd)),
+		OwnerReference: etcd.GetAsOwnerReference(),
 	}
 }
 

pkg/component/etcd/role/role.go

@@ -36,7 +36,7 @@ func (c component) Deploy(ctx context.Context) error {
 		role.Name = c.values.Name
 		role.Namespace = c.values.Namespace
 		role.Labels = c.values.Labels
-		role.OwnerReferences = c.values.OwnerReferences
+		role.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 		role.Rules = c.values.Rules
 		return nil
 	})

pkg/component/etcd/role/role_test.go

@@ -112,7 +112,7 @@ func verifyRoleValues(expected *rbacv1.Role, values *role.Values) {
 	Expect(expected.Name).To(Equal(values.Name))
 	Expect(expected.Labels).To(Equal(values.Labels))
 	Expect(expected.Namespace).To(Equal(values.Namespace))
-	Expect(expected.OwnerReferences).To(Equal(values.OwnerReferences))
+	Expect(expected.OwnerReferences).To(Equal([]metav1.OwnerReference{*values.OwnerReference}))
 	Expect(expected.Rules).To(MatchAllElements(testutils.RuleIterator, Elements{
 		"coordination.k8s.io": MatchFields(IgnoreExtras, Fields{
 			"APIGroups": MatchAllElements(testutils.StringArrayIterator, Elements{
@@ -187,15 +187,13 @@ func getTestRoleValues() *role.Values {
 				Verbs:     []string{"get", "list", "watch"},
 			},
 		},
-		OwnerReferences: []metav1.OwnerReference{
-			{
-				APIVersion:         v1alpha1.GroupVersion.String(),
-				Kind:               "etcd",
-				Name:               "test-etcd",
-				UID:                "123-456-789",
-				Controller:         pointer.Bool(true),
-				BlockOwnerDeletion: pointer.Bool(true),
-			},
+		OwnerReference: &metav1.OwnerReference{
+			APIVersion:         v1alpha1.GroupVersion.String(),
+			Kind:               "etcd",
+			Name:               "test-etcd",
+			UID:                "123-456-789",
+			Controller:         pointer.Bool(true),
+			BlockOwnerDeletion: pointer.Bool(true),
 		},
 	}
 }

pkg/component/etcd/role/values.go

@@ -27,8 +27,8 @@ type Values struct {
 	Namespace string
 	// Rules holds all the PolicyRules for this Role
 	Rules []rbacv1.PolicyRule
-	// OwnerReferences are the OwnerReferences of the Role.
-	OwnerReferences []metav1.OwnerReference
+	// OwnerReference are the OwnerReference of the Role.
+	OwnerReference *metav1.OwnerReference
 	// Labels are the labels of the Role.
 	Labels map[string]string
 }

pkg/component/etcd/role/values_helper.go

@@ -17,18 +17,15 @@ package role
 import (
 	druidv1alpha1 "github.com/gardener/etcd-druid/api/v1alpha1"
 	rbacv1 "k8s.io/api/rbac/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 // GenerateValues generates `role.Values` for the role component with the given `etcd` object.
 func GenerateValues(etcd *druidv1alpha1.Etcd) *Values {
 	return &Values{
-		Name:      etcd.GetRoleName(),
-		Namespace: etcd.Namespace,
-		Labels:    etcd.GetDefaultLabels(),
-		OwnerReferences: []metav1.OwnerReference{
-			etcd.GetAsOwnerReference(),
-		},
+		Name:           etcd.GetRoleName(),
+		Namespace:      etcd.Namespace,
+		Labels:         etcd.GetDefaultLabels(),
+		OwnerReference: etcd.GetAsOwnerReference(),
 		Rules: []rbacv1.PolicyRule{
 			{
 				APIGroups: []string{"coordination.k8s.io"},

pkg/component/etcd/role/values_helper_test.go

@@ -49,9 +49,7 @@ var _ = Describe("Role", func() {
 				"name":     "etcd",
 				"instance": etcd.Name,
 			},
-			OwnerReferences: []metav1.OwnerReference{
-				etcd.GetAsOwnerReference(),
-			},
+			OwnerReference: etcd.GetAsOwnerReference(),
 			Rules: []rbacv1.PolicyRule{
 				{
 					APIGroups: []string{"coordination.k8s.io"},

pkg/component/etcd/rolebinding/rolebinding.go

@@ -36,7 +36,7 @@ func (c component) Deploy(ctx context.Context) error {
 		roleBinding.Name = c.values.Name
 		roleBinding.Namespace = c.values.Namespace
 		roleBinding.Labels = c.values.Labels
-		roleBinding.OwnerReferences = c.values.OwnerReferences
+		roleBinding.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 		roleBinding.RoleRef = rbacv1.RoleRef{
 			APIGroup: "rbac.authorization.k8s.io",
 			Kind:     "Role",

pkg/component/etcd/rolebinding/rolebinding_test.go

@@ -136,7 +136,7 @@ func verifyRoleBindingValues(expected *rbacv1.RoleBinding, values *rolebinding.V
 	Expect(expected.Labels).To(Equal(values.Labels))
 	Expect(expected.Namespace).To(Equal(values.Namespace))
 	Expect(expected.Namespace).To(Equal(values.Namespace))
-	Expect(expected.OwnerReferences).To(Equal(values.OwnerReferences))
+	Expect(expected.OwnerReferences).To(Equal([]metav1.OwnerReference{*values.OwnerReference}))
 	Expect(expected.Subjects).To(Equal([]rbacv1.Subject{
 		{
 			Kind:      "ServiceAccount",
@@ -163,15 +163,13 @@ func getTestRoleBindingValues() *rolebinding.Values {
 		},
 		RoleName:           "test-role",
 		ServiceAccountName: "test-serviceaccount",
-		OwnerReferences: []metav1.OwnerReference{
-			{
-				APIVersion:         v1alpha1.GroupVersion.String(),
-				Kind:               "etcd",
-				Name:               "test-etcd",
-				UID:                "123-456-789",
-				Controller:         pointer.Bool(true),
-				BlockOwnerDeletion: pointer.Bool(true),
-			},
+		OwnerReference: &metav1.OwnerReference{
+			APIVersion:         v1alpha1.GroupVersion.String(),
+			Kind:               "etcd",
+			Name:               "test-etcd",
+			UID:                "123-456-789",
+			Controller:         pointer.Bool(true),
+			BlockOwnerDeletion: pointer.Bool(true),
 		},
 	}
 }

pkg/component/etcd/rolebinding/values.go

@@ -27,8 +27,8 @@ type Values struct {
 	// ServiceAccountName is the service account subject name for the RoleBinding.
 	// It is assumed that the ServiceAccount exists in the namespace where the etcd custom resource is created.
 	ServiceAccountName string
-	// OwnerReferences are the OwnerReferences of the RoleBinding.
-	OwnerReferences []metav1.OwnerReference
+	// OwnerReference are the OwnerReference of the RoleBinding.
+	OwnerReference *metav1.OwnerReference
 	// Labels are the labels of the RoleBinding.
 	Labels map[string]string
 }

pkg/component/etcd/rolebinding/values_helper.go

@@ -16,18 +16,15 @@ package rolebinding
 
 import (
 	druidv1alpha1 "github.com/gardener/etcd-druid/api/v1alpha1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 // GenerateValues generates `serviceaccount.Values` for the serviceaccount component with the given `etcd` object.
 func GenerateValues(etcd *druidv1alpha1.Etcd) *Values {
 	return &Values{
-		Name:      etcd.GetRoleBindingName(),
-		Namespace: etcd.Namespace,
-		Labels:    etcd.GetDefaultLabels(),
-		OwnerReferences: []metav1.OwnerReference{
-			etcd.GetAsOwnerReference(),
-		},
+		Name:               etcd.GetRoleBindingName(),
+		Namespace:          etcd.Namespace,
+		Labels:             etcd.GetDefaultLabels(),
+		OwnerReference:     etcd.GetAsOwnerReference(),
 		RoleName:           etcd.GetRoleName(),
 		ServiceAccountName: etcd.GetServiceAccountName(),
 	}

pkg/component/etcd/rolebinding/values_helper_test.go

@@ -46,9 +46,7 @@ var _ = Describe("RoleBinding", func() {
 			},
 			RoleName:           etcd.GetRoleName(),
 			ServiceAccountName: etcd.GetServiceAccountName(),
-			OwnerReferences: []metav1.OwnerReference{
-				etcd.GetAsOwnerReference(),
-			},
+			OwnerReference:     etcd.GetAsOwnerReference(),
 		}
 	)
 

pkg/component/etcd/service/service_client.go

@@ -20,14 +20,15 @@ import (
 	"github.com/gardener/etcd-druid/pkg/utils"
 	"github.com/gardener/gardener/pkg/controllerutils"
 	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
 )
 
 func (c *component) syncClientService(ctx context.Context, svc *corev1.Service) error {
 	_, err := controllerutils.GetAndCreateOrStrategicMergePatch(ctx, c.client, svc, func() error {
 		svc.Labels = utils.MergeStringMaps(c.values.Labels, c.values.ClientServiceLabels)
 		svc.Annotations = c.values.ClientServiceAnnotations
-		svc.OwnerReferences = c.values.OwnerReferences
+		svc.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 		svc.Spec.Type = corev1.ServiceTypeClusterIP
 		svc.Spec.SessionAffinity = corev1.ServiceAffinityNone
 		svc.Spec.Selector = c.values.SelectorLabels

pkg/component/etcd/service/service_peer.go

@@ -19,13 +19,14 @@ import (
 
 	"github.com/gardener/gardener/pkg/controllerutils"
 	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
 )
 
 func (c *component) syncPeerService(ctx context.Context, svc *corev1.Service) error {
 	_, err := controllerutils.GetAndCreateOrStrategicMergePatch(ctx, c.client, svc, func() error {
 		svc.Labels = c.values.Labels
-		svc.OwnerReferences = c.values.OwnerReferences
+		svc.OwnerReferences = []metav1.OwnerReference{*c.values.OwnerReference}
 		svc.Spec.Type = corev1.ServiceTypeClusterIP
 		svc.Spec.ClusterIP = corev1.ClusterIPNone
 		svc.Spec.SessionAffinity = corev1.ServiceAffinityNone

pkg/component/etcd/service/service_test.go

@@ -166,7 +166,7 @@ var _ = Describe("Service", func() {
 })
 
 func checkClientService(svc *corev1.Service, values Values) {
-	Expect(svc.OwnerReferences).To(Equal(values.OwnerReferences))
+	Expect(svc.OwnerReferences).To(Equal([]metav1.OwnerReference{*values.OwnerReference}))
 	Expect(svc.Labels).To(Equal(utils.MergeStringMaps(values.Labels, values.ClientServiceLabels)))
 	Expect(svc.Spec.Selector).To(Equal(values.SelectorLabels))
 	Expect(svc.Spec.Type).To(Equal(corev1.ServiceType("ClusterIP")))
@@ -193,7 +193,7 @@ func checkClientService(svc *corev1.Service, values Values) {
 }
 
 func checkPeerService(svc *corev1.Service, values Values) {
-	Expect(svc.OwnerReferences).To(Equal(values.OwnerReferences))
+	Expect(svc.OwnerReferences).To(Equal([]metav1.OwnerReference{*values.OwnerReference}))
 	Expect(svc.Labels).To(Equal(values.Labels))
 	Expect(svc.Spec.PublishNotReadyAddresses).To(BeTrue())
 	Expect(svc.Spec.Type).To(Equal(corev1.ServiceType("ClusterIP")))