Change signature on GetOwnerReference

A small refactoring of PipelineRun function. Change signature so it corresponds with the name.
From:

    func (pr *PipelineRun) GetOwnerReference() []metav1.OwnerReference

To:

    func (pr *PipelineRun) GetOwnerReference() metav1.OwnerReference

 This signature change leads to more _idiomatic code_ and avoids code like:

     pr.GetOwnerReference()[0]

 to be replaced with:

     pr.GetOwnerReference()

 This is a small Go function API change, but it does not change the type structure API (e.g. Yaml). Code that before this change used

     pr.GetOwnerReference()

 need to change the function call to

     []metav1.OwnerReference{pr.GetOwnerReference()}

pkg/apis/pipeline/v1alpha1/pipelinerun_types.go

@@ -152,10 +152,8 @@ func (pr *PipelineRun) GetTaskRunRef() corev1.ObjectReference {
 }
 
 // GetOwnerReference gets the pipeline run as owner reference for any related objects
-func (pr *PipelineRun) GetOwnerReference() []metav1.OwnerReference {
-	return []metav1.OwnerReference{
-		*metav1.NewControllerRef(pr, groupVersionKind),
-	}
+func (pr *PipelineRun) GetOwnerReference() metav1.OwnerReference {
+	return *metav1.NewControllerRef(pr, groupVersionKind)
 }
 
 // IsDone returns true if the PipelineRun's status indicates that it is done.

pkg/apis/pipeline/v1beta1/pipelinerun_types.go

@@ -73,10 +73,8 @@ func (pr *PipelineRun) GetTaskRunRef() corev1.ObjectReference {
 }
 
 // GetOwnerReference gets the pipeline run as owner reference for any related objects
-func (pr *PipelineRun) GetOwnerReference() []metav1.OwnerReference {
-	return []metav1.OwnerReference{
-		*metav1.NewControllerRef(pr, groupVersionKind),
-	}
+func (pr *PipelineRun) GetOwnerReference() metav1.OwnerReference {
+	return *metav1.NewControllerRef(pr, groupVersionKind)
 }
 
 // IsDone returns true if the PipelineRun's status indicates that it is done.

pkg/artifacts/artifact_storage_test.go

@@ -101,7 +101,7 @@ var (
 
 func GetPersistentVolumeClaim(size string, storageClassName *string) *corev1.PersistentVolumeClaim {
 	pvc := &corev1.PersistentVolumeClaim{
-		ObjectMeta: metav1.ObjectMeta{Name: "pipelineruntest-pvc", Namespace: pipelinerun.Namespace, OwnerReferences: pipelinerun.GetOwnerReference()},
+		ObjectMeta: metav1.ObjectMeta{Name: "pipelineruntest-pvc", Namespace: pipelinerun.Namespace, OwnerReferences: []metav1.OwnerReference{pipelinerun.GetOwnerReference()}},
 		Spec: corev1.PersistentVolumeClaimSpec{
 			AccessModes:      []corev1.PersistentVolumeAccessMode{corev1.ReadWriteOnce},
 			Resources:        corev1.ResourceRequirements{Requests: corev1.ResourceList{corev1.ResourceStorage: resource.MustParse(size)}},

pkg/artifacts/artifacts_storage.go

@@ -314,7 +314,7 @@ func GetPVCSpec(pr *v1alpha1.PipelineRun, pvcSize resource.Quantity, storageClas
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace:       pr.Namespace,
 			Name:            GetPVCName(pr),
-			OwnerReferences: pr.GetOwnerReference(),
+			OwnerReferences: []metav1.OwnerReference{pr.GetOwnerReference()},
 		},
 		Spec: corev1.PersistentVolumeClaimSpec{
 			AccessModes: []corev1.PersistentVolumeAccessMode{corev1.ReadWriteOnce},

pkg/reconciler/pipelinerun/pipelinerun.go

@@ -535,7 +535,7 @@ func (c *Reconciler) reconcile(ctx context.Context, pr *v1alpha1.PipelineRun) er
 
 	if pipelineState.IsBeforeFirstTaskRun() && pr.HasVolumeClaimTemplate() {
 		// create workspace PVC from template
-		if err = c.pvcHandler.CreatePersistentVolumeClaimsForWorkspaces(pr.Spec.Workspaces, pr.GetOwnerReference()[0], pr.Namespace); err != nil {
+		if err = c.pvcHandler.CreatePersistentVolumeClaimsForWorkspaces(pr.Spec.Workspaces, pr.GetOwnerReference(), pr.Namespace); err != nil {
 			c.Logger.Errorf("Failed to create PVC for PipelineRun %s: %v", pr.Name, err)
 			pr.Status.SetCondition(&apis.Condition{
 				Type:   apis.ConditionSucceeded,
@@ -708,7 +708,7 @@ func (c *Reconciler) createTaskRun(rprt *resources.ResolvedPipelineRunTask, pr *
 		ObjectMeta: metav1.ObjectMeta{
 			Name:            rprt.TaskRunName,
 			Namespace:       pr.Namespace,
-			OwnerReferences: pr.GetOwnerReference(),
+			OwnerReferences: []metav1.OwnerReference{pr.GetOwnerReference()},
 			Labels:          getTaskrunLabels(pr, rprt.PipelineTask.Name),
 			Annotations:     getTaskrunAnnotations(pr),
 		},
@@ -735,7 +735,7 @@ func (c *Reconciler) createTaskRun(rprt *resources.ResolvedPipelineRunTask, pr *
 	for _, ws := range rprt.PipelineTask.Workspaces {
 		taskWorkspaceName, pipelineWorkspaceName := ws.Name, ws.Workspace
 		if b, hasBinding := pipelineRunWorkspaces[pipelineWorkspaceName]; hasBinding {
-			tr.Spec.Workspaces = append(tr.Spec.Workspaces, taskWorkspaceByWorkspaceVolumeSource(b, taskWorkspaceName, pr.GetOwnerReference()[0]))
+			tr.Spec.Workspaces = append(tr.Spec.Workspaces, taskWorkspaceByWorkspaceVolumeSource(b, taskWorkspaceName, pr.GetOwnerReference()))
 		} else {
 			return nil, fmt.Errorf("expected workspace %q to be provided by pipelinerun for pipeline task %q", pipelineWorkspaceName, rprt.PipelineTask.Name)
 		}
@@ -887,7 +887,7 @@ func (c *Reconciler) makeConditionCheckContainer(rprt *resources.ResolvedPipelin
 		ObjectMeta: metav1.ObjectMeta{
 			Name:            rcc.ConditionCheckName,
 			Namespace:       pr.Namespace,
-			OwnerReferences: pr.GetOwnerReference(),
+			OwnerReferences: []metav1.OwnerReference{pr.GetOwnerReference()},
 			Labels:          labels,
 			Annotations:     getTaskrunAnnotations(pr), // Propagate annotations from PipelineRun to TaskRun.
 		},