✨ implement helpers for add/remove finalizer

Author: alexeldeib

pkg/controller/controllerutil/controllerutil.go

@@ -22,6 +22,7 @@ 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"
@@ -168,3 +169,47 @@ 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) {
+	f := o.GetFinalizers()
+	for _, e := range f {
+		if e == finalizer {
+			return
+		}
+	}
+	o.SetFinalizers(append(f, finalizer))
+}
+
+// AddFinalizerWithError 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 AddFinalizerWithError(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) {
+	f := o.GetFinalizers()
+	for i, e := range f {
+		if e == finalizer {
+			f = append(f[:i], f[i+1:]...)
+		}
+	}
+	o.SetFinalizers(f)
+}
+
+// RemoveFinalizerWithError 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 RemoveFinalizerWithError(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("AddFinalizerWithError", func() {
+			It("should return an error if object can't provide accessor", func() {
+				Expect(controllerutil.AddFinalizerWithError(obj, testFinalizer)).To(HaveOccurred())
+			})
+		})
+
+		Describe("RemoveFinalizerWithError", func() {
+			It("should return an error if object can't provide accessor", func() {
+				Expect(controllerutil.RemoveFinalizerWithError(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
 }