StatefulSet: Set DefaultGarbageCollectionPolicy to OrphanDependents.

Now that StatefulSet adds ControllerRef to Pods it creates,
we need to set this default so legacy behavior is maintained.

pkg/registry/apps/petset/BUILD

@@ -25,6 +25,7 @@ go_library(
         "//vendor:k8s.io/apimachinery/pkg/util/validation/field",
         "//vendor:k8s.io/apiserver/pkg/endpoints/request",
         "//vendor:k8s.io/apiserver/pkg/registry/generic",
+        "//vendor:k8s.io/apiserver/pkg/registry/rest",
         "//vendor:k8s.io/apiserver/pkg/storage",
         "//vendor:k8s.io/apiserver/pkg/storage/names",
     ],
@@ -40,6 +41,7 @@ go_test(
         "//pkg/apis/apps:go_default_library",
         "//vendor:k8s.io/apimachinery/pkg/apis/meta/v1",
         "//vendor:k8s.io/apiserver/pkg/endpoints/request",
+        "//vendor:k8s.io/apiserver/pkg/registry/rest",
     ],
 )
 

pkg/registry/apps/petset/strategy.go

@@ -26,6 +26,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
 	"k8s.io/apiserver/pkg/registry/generic"
+	"k8s.io/apiserver/pkg/registry/rest"
 	"k8s.io/apiserver/pkg/storage"
 	"k8s.io/apiserver/pkg/storage/names"
 	"k8s.io/kubernetes/pkg/api"
@@ -42,6 +43,12 @@ type statefulSetStrategy struct {
 // Strategy is the default logic that applies when creating and updating Replication StatefulSet objects.
 var Strategy = statefulSetStrategy{api.Scheme, names.SimpleNameGenerator}
 
+// DefaultGarbageCollectionPolicy returns Orphan because that was the default
+// behavior before the server-side garbage collection was implemented.
+func (statefulSetStrategy) DefaultGarbageCollectionPolicy() rest.GarbageCollectionPolicy {
+	return rest.OrphanDependents
+}
+
 // NamespaceScoped returns true because all StatefulSet' need to be within a namespace.
 func (statefulSetStrategy) NamespaceScoped() bool {
 	return true

pkg/registry/apps/petset/strategy_test.go

@@ -21,6 +21,7 @@ import (
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/registry/rest"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/apis/apps"
 )
@@ -62,7 +63,7 @@ func TestStatefulSetStrategy(t *testing.T) {
 	}
 	errs := Strategy.Validate(ctx, ps)
 	if len(errs) != 0 {
-		t.Errorf("Unexpected error validating %v", errs)
+		t.Errorf("unexpected error validating %v", errs)
 	}
 
 	// Just Spec.Replicas is allowed to change
@@ -77,14 +78,21 @@ func TestStatefulSetStrategy(t *testing.T) {
 	Strategy.PrepareForUpdate(ctx, validPs, ps)
 	errs = Strategy.ValidateUpdate(ctx, validPs, ps)
 	if len(errs) != 0 {
-		t.Errorf("Updating spec.Replicas is allowed on a statefulset: %v", errs)
+		t.Errorf("updating spec.Replicas is allowed on a statefulset: %v", errs)
 	}
 
 	validPs.Spec.Selector = &metav1.LabelSelector{MatchLabels: map[string]string{"a": "bar"}}
 	Strategy.PrepareForUpdate(ctx, validPs, ps)
 	errs = Strategy.ValidateUpdate(ctx, validPs, ps)
 	if len(errs) == 0 {
-		t.Errorf("Expected a validation error since updates are disallowed on statefulsets.")
+		t.Errorf("expected a validation error since updates are disallowed on statefulsets.")
+	}
+
+	// Make sure we correctly implement the interface.
+	// Otherwise a typo could silently change the default.
+	var gcds rest.GarbageCollectionDeleteStrategy = Strategy
+	if got, want := gcds.DefaultGarbageCollectionPolicy(), rest.OrphanDependents; got != want {
+		t.Errorf("DefaultGarbageCollectionPolicy() = %#v, want %#v", got, want)
 	}
 }
 
@@ -140,6 +148,6 @@ func TestStatefulSetStatusStrategy(t *testing.T) {
 	}
 	errs := StatusStrategy.ValidateUpdate(ctx, newPS, oldPS)
 	if len(errs) != 0 {
-		t.Errorf("Unexpected error %v", errs)
+		t.Errorf("unexpected error %v", errs)
 	}
 }