feat: custom equalities in CreateOrUpdate

pkg/controller/controllerutil/controllerutil.go

@@ -25,6 +25,7 @@ import (
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/conversion"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/utils/ptr"
@@ -274,6 +275,11 @@ const ( // They should complete the sentence "Deployment default/foo has been ..
 // Note: changes made by MutateFn to any sub-resource (status...), will be
 // discarded.
 func CreateOrUpdate(ctx context.Context, c client.Client, obj client.Object, f MutateFn) (OperationResult, error) {
+	return CreateOrUpdateWithEqualities(ctx, c, obj, equality.Semantic, f)
+}
+
+// CreateOrUpdateWithEqualities is like CreateOrUpdate but allows customizing the equality check.
+func CreateOrUpdateWithEqualities(ctx context.Context, c client.Client, obj client.Object, eq conversion.Equalities, f MutateFn) (OperationResult, error) {
 	key := client.ObjectKeyFromObject(obj)
 	if err := c.Get(ctx, key, obj); err != nil {
 		if !apierrors.IsNotFound(err) {
@@ -293,7 +299,7 @@ func CreateOrUpdate(ctx context.Context, c client.Client, obj client.Object, f M
 		return OperationResultNone, err
 	}
 
-	if equality.Semantic.DeepEqual(existing, obj) {
+	if eq.DeepEqual(existing, obj) {
 		return OperationResultNone, nil
 	}
 

pkg/controller/controllerutil/controllerutil_test.go

@@ -26,6 +26,7 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	extensionsv1beta1 "k8s.io/api/extensions/v1beta1"
+	"k8s.io/apimachinery/pkg/api/equality"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
@@ -507,6 +508,30 @@ var _ = Describe("Controllerutil", func() {
 			Expect(op).To(BeEquivalentTo(controllerutil.OperationResultNone))
 		})
 
+		It("uses custom equality check as-is", func() {
+			op, err := controllerutil.CreateOrUpdate(context.TODO(), c, deploy, specr)
+
+			Expect(op).To(BeEquivalentTo(controllerutil.OperationResultCreated))
+			Expect(err).NotTo(HaveOccurred())
+
+			eq := equality.Semantic.Copy()
+			eq.AddFunc(func(a, b appsv1.DeploymentStrategy) bool {
+				// intentionallity ignore and return true
+				return true
+			})
+			op, err = controllerutil.CreateOrUpdateWithEqualities(context.TODO(), c, deploy, eq, func() error {
+				deploy.Spec.Strategy = appsv1.DeploymentStrategy{
+					Type: appsv1.RecreateDeploymentStrategyType, // just any change
+				}
+				return nil
+			})
+			By("returning no error")
+			Expect(err).NotTo(HaveOccurred())
+
+			By("returning OperationResultNone")
+			Expect(op).To(BeEquivalentTo(controllerutil.OperationResultNone))
+		})
+
 		It("errors when MutateFn changes object name on creation", func() {
 			op, err := controllerutil.CreateOrUpdate(context.TODO(), c, deploy, func() error {
 				Expect(specr()).To(Succeed())