Merge pull request #48319 from nilebox/nilebox/controller-ref

Automatic merge from submit-queue (batch tested with PRs 48279, 48566, 48319, 48794, 47952)

Helper methods dealing with ControllerRef

**What this PR does / why we need it**:
Adds helper methods for working with **controllerRef** (controller's `OwnerReference`).

It is based on the existing code from Kubernetes plus extracting some common logic:
- `NewControllerRef` is based on examples from [daemon controller](https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/daemon/daemoncontroller.go#L1223), [deployment controller](https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/deployment/sync.go#L649), [job controller](https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/job/utils.go#L34)
- `GetControllerOf` is copied from [controller_ref_manager.go](https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/controller_ref_manager.go#L36)
- `IsControlledBy` is a common logic extracted from resource controllers: [deployment_util.go#L568](https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/deployment/util/deployment_util.go#L568), [history.go#L276](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubectl/history.go#L276) and many others.

It will also be useful for writing custom resource controllers, for example [service-catalog#979](https://github.com/kubernetes-incubator/service-catalog/pull/979)

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/BUILD

@@ -11,6 +11,7 @@ load(
 go_test(
     name = "go_default_test",
     srcs = [
+        "controller_ref_test.go",
         "duration_test.go",
         "group_version_test.go",
         "helpers_test.go",
@@ -25,12 +26,14 @@ go_test(
         "//vendor/github.com/ghodss/yaml:go_default_library",
         "//vendor/github.com/ugorji/go/codec:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/labels:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
     ],
 )
 
 go_library(
     name = "go_default_library",
     srcs = [
+        "controller_ref.go",
         "conversion.go",
         "doc.go",
         "duration.go",

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/controller_ref.go

@@ -0,0 +1,54 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// IsControlledBy checks if the  object has a controllerRef set to the given owner
+func IsControlledBy(obj Object, owner Object) bool {
+	ref := GetControllerOf(obj)
+	if ref == nil {
+		return false
+	}
+	return ref.UID == owner.GetUID()
+}
+
+// GetControllerOf returns a pointer to a copy of the controllerRef if controllee has a controller
+func GetControllerOf(controllee Object) *OwnerReference {
+	for _, ref := range controllee.GetOwnerReferences() {
+		if ref.Controller != nil && *ref.Controller {
+			return &ref
+		}
+	}
+	return nil
+}
+
+// NewControllerRef creates an OwnerReference pointing to the given owner.
+func NewControllerRef(owner Object, gvk schema.GroupVersionKind) *OwnerReference {
+	blockOwnerDeletion := true
+	isController := true
+	return &OwnerReference{
+		APIVersion:         gvk.GroupVersion().String(),
+		Kind:               gvk.Kind,
+		Name:               owner.GetName(),
+		UID:                owner.GetUID(),
+		BlockOwnerDeletion: &blockOwnerDeletion,
+		Controller:         &isController,
+	}
+}

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/controller_ref_test.go

@@ -0,0 +1,133 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import (
+	"testing"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+type metaObj struct {
+	ObjectMeta
+	TypeMeta
+}
+
+func TestNewControllerRef(t *testing.T) {
+	gvk := schema.GroupVersionKind{
+		Group:   "group",
+		Version: "v1",
+		Kind:    "Kind",
+	}
+	obj1 := &metaObj{
+		ObjectMeta: ObjectMeta{
+			Name: "name",
+			UID:  "uid1",
+		},
+	}
+	controllerRef := NewControllerRef(obj1, gvk)
+	if controllerRef.UID != obj1.UID {
+		t.Errorf("Incorrect UID: %s", controllerRef.UID)
+	}
+	if controllerRef.Controller == nil || *controllerRef.Controller != true {
+		t.Error("Controller must be set to true")
+	}
+	if controllerRef.BlockOwnerDeletion == nil || *controllerRef.BlockOwnerDeletion != true {
+		t.Error("BlockOwnerDeletion must be set to true")
+	}
+	if controllerRef.APIVersion == "" ||
+		controllerRef.Kind == "" ||
+		controllerRef.Name == "" {
+		t.Errorf("All controllerRef fields must be set: %v", controllerRef)
+	}
+}
+
+func TestGetControllerOf(t *testing.T) {
+	gvk := schema.GroupVersionKind{
+		Group:   "group",
+		Version: "v1",
+		Kind:    "Kind",
+	}
+	obj1 := &metaObj{
+		ObjectMeta: ObjectMeta{
+			UID:  "uid1",
+			Name: "name1",
+		},
+	}
+	controllerRef := NewControllerRef(obj1, gvk)
+	var falseRef = false
+	obj2 := &metaObj{
+		ObjectMeta: ObjectMeta{
+			UID:  "uid2",
+			Name: "name1",
+			OwnerReferences: []OwnerReference{
+				{
+					Name:       "owner1",
+					Controller: &falseRef,
+				},
+				*controllerRef,
+				{
+					Name:       "owner2",
+					Controller: &falseRef,
+				},
+			},
+		},
+	}
+
+	if GetControllerOf(obj1) != nil {
+		t.Error("GetControllerOf must return null")
+	}
+	c := GetControllerOf(obj2)
+	if c.Name != controllerRef.Name || c.UID != controllerRef.UID {
+		t.Errorf("Incorrect result of GetControllerOf: %v", c)
+	}
+}
+
+func TestIsControlledBy(t *testing.T) {
+	gvk := schema.GroupVersionKind{
+		Group:   "group",
+		Version: "v1",
+		Kind:    "Kind",
+	}
+	obj1 := &metaObj{
+		ObjectMeta: ObjectMeta{
+			UID: "uid1",
+		},
+	}
+	obj2 := &metaObj{
+		ObjectMeta: ObjectMeta{
+			UID: "uid2",
+			OwnerReferences: []OwnerReference{
+				*NewControllerRef(obj1, gvk),
+			},
+		},
+	}
+	obj3 := &metaObj{
+		ObjectMeta: ObjectMeta{
+			UID: "uid3",
+			OwnerReferences: []OwnerReference{
+				*NewControllerRef(obj2, gvk),
+			},
+		},
+	}
+	if !IsControlledBy(obj2, obj1) || !IsControlledBy(obj3, obj2) {
+		t.Error("Incorrect IsControlledBy result: false")
+	}
+	if IsControlledBy(obj3, obj1) {
+		t.Error("Incorrect IsControlledBy result: true")
+	}
+}