Ensure MachineSet controller won't orphan resources

To ensure that the MachineSet controller won't orphan infrastructure
config or bootstrap config resources as the result of an incomplete
reconcile followed by cluster deletion, add an OwnerReference during
creation of these resources by the MachineSet controller.

Author: zjs

controllers/external/util.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/pkg/errors"
 	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
@@ -42,6 +43,12 @@ func Get(c client.Client, ref *corev1.ObjectReference, namespace string) (*unstr
 
 // CloneTemplate uses the client and the reference to create a new object from the template.
 func CloneTemplate(c client.Client, ref *corev1.ObjectReference, namespace string) (*unstructured.Unstructured, error) {
+	return CloneTemplateWithOwner(c, ref, namespace, nil)
+}
+
+// CloneTemplateWithOwner uses the client and the reference to create a new object, owned by the
+// indicated resource, from the supplied template.
+func CloneTemplateWithOwner(c client.Client, ref *corev1.ObjectReference, namespace string, owner *metav1.OwnerReference) (*unstructured.Unstructured, error) {
 	from, err := Get(c, ref, namespace)
 	if err != nil {
 		return nil, err
@@ -56,14 +63,17 @@ func CloneTemplate(c client.Client, ref *corev1.ObjectReference, namespace strin
 	// Create the unstructured object from the template.
 	to := &unstructured.Unstructured{Object: template}
 	to.SetResourceVersion("")
-	to.SetOwnerReferences(nil)
 	to.SetFinalizers(nil)
 	to.SetUID("")
 	to.SetSelfLink("")
 	to.SetName("")
 	to.SetGenerateName(fmt.Sprintf("%s-", from.GetName()))
 	to.SetNamespace(namespace)
 
+	if owner != nil {
+		to.SetOwnerReferences([]metav1.OwnerReference{*owner})
+	}
+
 	// Set the object APIVersion.
 	if to.GetAPIVersion() == "" {
 		to.SetAPIVersion(ref.APIVersion)

controllers/machineset_controller.go

@@ -259,7 +259,7 @@ func (r *MachineSetReconciler) syncReplicas(ms *clusterv1.MachineSet, machines [
 				err                          error
 			)
 
-			infraConfig, err = external.CloneTemplate(r.Client, &machine.Spec.InfrastructureRef, machine.Namespace)
+			infraConfig, err = external.CloneTemplateWithOwner(r.Client, &machine.Spec.InfrastructureRef, machine.Namespace, metav1.NewControllerRef(ms, machineSetKind))
 			if err != nil {
 				return errors.Wrapf(err, "failed to clone infrastructure configuration for MachineSet %q in namespace %q", ms.Name, ms.Namespace)
 			}
@@ -271,7 +271,7 @@ func (r *MachineSetReconciler) syncReplicas(ms *clusterv1.MachineSet, machines [
 			}
 
 			if machine.Spec.Bootstrap.ConfigRef != nil {
-				bootstrapConfig, err = external.CloneTemplate(r.Client, machine.Spec.Bootstrap.ConfigRef, machine.Namespace)
+				bootstrapConfig, err = external.CloneTemplateWithOwner(r.Client, machine.Spec.Bootstrap.ConfigRef, machine.Namespace, metav1.NewControllerRef(ms, machineSetKind))
 				if err != nil {
 					return errors.Wrapf(err, "failed to clone bootstrap configuration for MachineSet %q in namespace %q", ms.Name, ms.Namespace)
 				}