✨ implement helpers for add/remove finalizer

Author: alexeldeib

go.mod

@@ -32,7 +32,6 @@ require (
 	go.uber.org/zap v1.9.1
 	golang.org/x/crypto v0.0.0-20180820150726-614d502a4dac // indirect
 	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be // indirect
-	golang.org/x/sync v0.0.0-20190423024810-112230192c58 // indirect
 	golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2 // indirect
 	gomodules.xyz/jsonpatch/v2 v2.0.1
 	google.golang.org/appengine v1.1.0 // indirect
@@ -44,7 +43,7 @@ require (
 	k8s.io/apimachinery v0.0.0-20190404173353-6a84e37a896d
 	k8s.io/client-go v11.0.1-0.20190409021438-1a26190bd76a+incompatible
 	k8s.io/kube-openapi v0.0.0-20180731170545-e3762e86a74c // indirect
-	k8s.io/utils v0.0.0-20190506122338-8fab8cb257d5 // indirect
+	k8s.io/utils v0.0.0-20190506122338-8fab8cb257d5
 	sigs.k8s.io/testing_frameworks v0.1.1
 	sigs.k8s.io/yaml v1.1.0
 )

pkg/controller/controllerutil/controllerutil.go

@@ -22,9 +22,11 @@ import (
 	"reflect"
 
 	"k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/sets"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/client/apiutil"
 )
@@ -168,3 +170,39 @@ func mutate(f MutateFn, key client.ObjectKey, obj runtime.Object) error {
 
 // MutateFn is a function which mutates the existing object into it's desired state.
 type MutateFn func() error
+
+// AddFinalizer accepts a metav1 object and adds the provided finalizer if not present.
+func AddFinalizer(o metav1.Object, finalizer string) {
+	finalizers := sets.NewString(o.GetFinalizers()...)
+	finalizers.Insert(finalizer)
+	o.SetFinalizers(finalizers.List())
+}
+
+// AddFinalizerIfPossible tries to convert a runtime object to a metav1 object and add the provided finalizer.
+// It returns an error if the provided object cannot provide an accessor.
+func AddFinalizerIfPossible(o runtime.Object, finalizer string) error {
+	m, err := meta.Accessor(o)
+	if err != nil {
+		return err
+	}
+	AddFinalizer(m, finalizer)
+	return nil
+}
+
+// RemoveFinalizer accepts a metav1 object and removes the provided finalizer if present.
+func RemoveFinalizer(o metav1.Object, finalizer string) {
+	finalizers := sets.NewString(o.GetFinalizers()...)
+	finalizers.Delete(finalizer)
+	o.SetFinalizers(finalizers.List())
+}
+
+// RemoveFinalizerIfPossible tries to convert a runtime object to a metav1 object and remove the provided finalizer.
+// It returns an error if the provided object cannot provide an accessor.
+func RemoveFinalizerIfPossible(o runtime.Object, finalizer string) error {
+	m, err := meta.Accessor(o)
+	if err != nil {
+		return err
+	}
+	RemoveFinalizer(m, finalizer)
+	return nil
+}

pkg/controller/controllerutil/controllerutil_test.go

@@ -265,10 +265,63 @@ var _ = Describe("Controllerutil", func() {
 			Expect(err).To(HaveOccurred())
 		})
 	})
+
+	Describe("Finalizers", func() {
+		var obj runtime.Object = &errRuntimeObj{}
+		var deploy *appsv1.Deployment
+
+		Describe("AddFinalizeIfPossible", func() {
+			It("should return an error if object can't provide accessor", func() {
+				Expect(controllerutil.AddFinalizerIfPossible(obj, testFinalizer)).To(HaveOccurred())
+			})
+		})
+
+		Describe("RemoveFinalizeIfPossible", func() {
+			It("should return an error if object can't provide accessor", func() {
+				Expect(controllerutil.RemoveFinalizerIfPossible(obj, testFinalizer)).To(HaveOccurred())
+			})
+		})
+
+		Describe("AddFinalizer", func() {
+			deploy = &appsv1.Deployment{
+				ObjectMeta: metav1.ObjectMeta{
+					Finalizers: []string{},
+				},
+			}
+
+			It("should add the finalizer when not present", func() {
+				controllerutil.AddFinalizer(deploy, testFinalizer)
+				Expect(deploy.ObjectMeta.GetFinalizers()).To(Equal([]string{testFinalizer}))
+			})
+
+			It("should not add the finalizer when already present", func() {
+				controllerutil.AddFinalizer(deploy, testFinalizer)
+				Expect(deploy.ObjectMeta.GetFinalizers()).To(Equal([]string{testFinalizer}))
+			})
+		})
+
+		Describe("RemoveFinalizer", func() {
+			It("should remove finalizer if present", func() {
+				controllerutil.RemoveFinalizer(deploy, testFinalizer)
+				Expect(deploy.ObjectMeta.GetFinalizers()).To(Equal([]string{}))
+			})
+		})
+	})
 })
 
+const testFinalizer = "foo.bar.baz"
+
+var _ runtime.Object = &errRuntimeObj{}
 var _ metav1.Object = &errMetaObj{}
 
+type errRuntimeObj struct {
+	runtime.TypeMeta
+}
+
+func (o *errRuntimeObj) DeepCopyObject() runtime.Object {
+	return &errRuntimeObj{}
+}
+
 type errMetaObj struct {
 	metav1.ObjectMeta
 }