address PR feedback

Author: Wieneo

.gitignore

@@ -23,4 +23,3 @@ TODO
 
 vendor
 out
-certs

charts/gardener-extension-acl/templates/rbac.yaml

@@ -133,6 +133,7 @@ rules:
   - create
   - update
   - patch
+  - delete
 - apiGroups:
   - networking.istio.io
   resources:

cmd/gardener-extension-acl/app/app.go

@@ -107,8 +107,13 @@ func (o *Options) run(ctx context.Context) error {
 
 	// TODO(Wieneo): Remove this once a couple extension versions included the migration code
 	// migration code: remove mutating webhook from cluster as it is not served by this controller anymore
-	if err := client.IgnoreNotFound(mgr.GetClient().Delete(ctx, &admissionregistrationv1.MutatingWebhookConfiguration{ObjectMeta: metav1.ObjectMeta{Name: ExtensionName}})); err != nil {
-		return fmt.Errorf("could not delete mutatingwebhook %s: %s", ExtensionName, err)
+	if err := mgr.Add(manager.RunnableFunc(func(ctx context.Context) error {
+		if err := client.IgnoreNotFound(mgr.GetClient().Delete(ctx, &admissionregistrationv1.MutatingWebhookConfiguration{ObjectMeta: metav1.ObjectMeta{Name: ExtensionName}})); err != nil {
+			return fmt.Errorf("could not delete mutatingwebhook %s: %s", ExtensionName, err)
+		}
+		return nil
+	})); err != nil {
+		return fmt.Errorf("could not add runnable to manager: %s", err)
 	}
 
 	if err := mgr.Start(ctx); err != nil {