pkg/kubernetes/kubernetes.go

// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you 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 kubernetes

import (
	jsonpatch "github.com/evanphx/json-patch"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
)

// ApplyOverlay applies an overlay using JSON patch strategy over the current Object in place.
func ApplyOverlay(current, overlay runtime.Object) error {
	cj, err := runtime.Encode(unstructured.UnstructuredJSONScheme, current)
	if err != nil {
		return err
	}
	uj, err := runtime.Encode(unstructured.UnstructuredJSONScheme, overlay)
	if err != nil {
		return err
	}
	merged, err := jsonpatch.MergePatch(cj, uj)
	if err != nil {
		return err
	}
	return runtime.DecodeInto(unstructured.UnstructuredJSONScheme, merged, current)
}