Merge pull request #453 from rramkumar1/finalizer-utils-refactor

Add JSONMerge patch utilities and move some files around

pkg/utils/finalizer.go

@@ -14,11 +14,7 @@ limitations under the License.
 package utils
 
 import (
-	"encoding/json"
-	"fmt"
-
 	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/util/strategicpatch"
 	"k8s.io/kubernetes/pkg/util/slice"
 )
 
@@ -39,24 +35,3 @@ func NeedToAddFinalizer(m meta_v1.ObjectMeta, key string) bool {
 func hasFinalizer(m meta_v1.ObjectMeta, key string) bool {
 	return slice.ContainsString(m.Finalizers, key, nil)
 }
-
-// GetPatchBytes returns a patch which is the difference between the old and new objects.
-// Note: refStruct is a empty struct of the type which the patch is being generated for.
-func GetPatchBytes(old interface{}, cur interface{}, refStruct interface{}) ([]byte, error) {
-	oldBytes, err := json.Marshal(old)
-	if err != nil {
-		return nil, fmt.Errorf("failed to marshal old object: %v", err)
-	}
-
-	newBytes, err := json.Marshal(cur)
-	if err != nil {
-		return nil, fmt.Errorf("failed to marshal new object: %v", err)
-	}
-
-	patchBytes, err := strategicpatch.CreateTwoWayMergePatch(oldBytes, newBytes, refStruct)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create patch: %v", err)
-	}
-
-	return patchBytes, nil
-}

pkg/utils/patch.go

@@ -0,0 +1,91 @@
+/*
+Copyright 2018 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 utils
+
+import (
+	"encoding/json"
+	"fmt"
+
+	api_v1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/util/jsonmergepatch"
+	"k8s.io/apimachinery/pkg/util/strategicpatch"
+)
+
+// StrategicMergePatchBytes returns a patch between the old and new object using a strategic merge patch.
+// Note: refStruct is a empty struct of the type which the patch is being generated for.
+func StrategicMergePatchBytes(old, cur, refStruct interface{}) ([]byte, error) {
+	oldBytes, err := json.Marshal(old)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal old object: %v", err)
+	}
+
+	newBytes, err := json.Marshal(cur)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal new object: %v", err)
+	}
+
+	patchBytes, err := strategicpatch.CreateTwoWayMergePatch(oldBytes, newBytes, refStruct)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create patch: %v", err)
+	}
+
+	return patchBytes, nil
+}
+
+// JSONMergePatchBytes returns a patch between the old and new object using a JSON merge patch.
+func JSONMergePatchBytes(old, cur interface{}) ([]byte, error) {
+	oldBytes, err := json.Marshal(old)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal old object: %v", err)
+	}
+
+	newBytes, err := json.Marshal(cur)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal new object: %v", err)
+	}
+
+	lastAppliedBytes, err := lastAppliedConfigurationBytes(old)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get last applied config for old object: %v", err)
+	}
+
+	patchBytes, err := jsonmergepatch.CreateThreeWayJSONMergePatch(lastAppliedBytes, newBytes, oldBytes)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create patch: %v", err)
+	}
+
+	return patchBytes, nil
+}
+
+// lastAppliedConfigurationBytes returns the bytes of the original configuration of an object
+// from the annotation, or nil if no annotation is found. This is needed for the 3-way JSON merge patch.
+func lastAppliedConfigurationBytes(obj interface{}) ([]byte, error) {
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return nil, err
+	}
+
+	annotations := accessor.GetAnnotations()
+	if annotations == nil {
+		return nil, nil
+	}
+
+	original, ok := annotations[api_v1.LastAppliedConfigAnnotation]
+	if !ok {
+		return nil, nil
+	}
+
+	return []byte(original), nil
+}

pkg/utils/patch_test.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2018 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 utils
+
+import (
+	"testing"
+
+	extensions "k8s.io/api/extensions/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestStrategicMergePatchBytes(t *testing.T) {
+	// Patch an Ingress w/ a finalizer
+	ing := &extensions.Ingress{}
+	updated := &extensions.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Finalizers: []string{"foo"},
+		},
+	}
+	b, err := StrategicMergePatchBytes(ing, updated, extensions.Ingress{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := `{"metadata":{"finalizers":["foo"]}}`
+	if string(b) != expected {
+		t.Errorf("StrategicMergePatchBytes(%+v, %+v) = %s ; want %s", ing, updated, string(b), expected)
+	}
+
+	// Patch an Ingress with the finalizer removed
+	ing = updated
+	updated = &extensions.Ingress{}
+	b, err = StrategicMergePatchBytes(ing, updated, extensions.Ingress{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected = `{"metadata":{"finalizers":null}}`
+	if string(b) != expected {
+		t.Errorf("StrategicMergePatchBytes(%+v, %+v) = %s ; want %s", ing, updated, string(b), expected)
+	}
+}
+
+func TestJSONMergePatchBytes(t *testing.T) {
+	// Patch an Ingress w/ a finalizer
+	ing := &extensions.Ingress{}
+	updated := &extensions.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Finalizers: []string{"foo"},
+		},
+	}
+	b, err := JSONMergePatchBytes(ing, updated)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := `{"metadata":{"creationTimestamp":null,"finalizers":["foo"]}}`
+	if string(b) != expected {
+		t.Errorf("JSONMergePatchBytes(%+v, %+v) = %s ; want %s", ing, updated, string(b), expected)
+	}
+
+	// Patch an Ingress with the finalizer removed
+	ing = updated
+	updated = &extensions.Ingress{}
+	b, err = JSONMergePatchBytes(ing, updated)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected = `{"metadata":{"creationTimestamp":null}}`
+	if string(b) != expected {
+		t.Errorf("JSONMergePatchBytes(%+v, %+v) = %s ; want %s", ing, updated, string(b), expected)
+	}
+}