utils/kubernetes/loader.go

/*
 * Licensed to the 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.  The 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 (
	"encoding/json"
	"fmt"

	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/serializer"
	"k8s.io/apimachinery/pkg/util/yaml"
	ctrl "sigs.k8s.io/controller-runtime/pkg/client"
)

// LoadResourceFromYaml returns a Kubernetes resource from its serialized YAML definition.
func LoadResourceFromYaml(scheme *runtime.Scheme, data string) (ctrl.Object, error) {
	source := []byte(data)
	jsonSource, err := yaml.ToJSON(source)
	if err != nil {
		return nil, err
	}
	u := unstructured.Unstructured{}
	err = u.UnmarshalJSON(jsonSource)
	if err != nil {
		return nil, err
	}
	ro, err := runtimeObjectFromUnstructured(scheme, &u)
	if err != nil {
		return nil, err
	}
	o, ok := ro.(ctrl.Object)
	if !ok {
		return nil, fmt.Errorf("type assertion failed: %v", ro)
	}

	return o, nil
}

// LoadUnstructuredFromYaml returns an unstructured resource from its serialized YAML definition.
func LoadUnstructuredFromYaml(data string) (ctrl.Object, error) {
	source, err := yaml.ToJSON([]byte(data))
	if err != nil {
		return nil, err
	}
	var obj map[string]interface{}
	if err = json.Unmarshal(source, &obj); err != nil {
		return nil, err
	}
	return &unstructured.Unstructured{
		Object: obj,
	}, nil
}

func runtimeObjectFromUnstructured(scheme *runtime.Scheme, u *unstructured.Unstructured) (runtime.Object, error) {
	gvk := u.GroupVersionKind()
	codecs := serializer.NewCodecFactory(scheme)
	decoder := codecs.UniversalDecoder(gvk.GroupVersion())

	b, err := u.MarshalJSON()
	if err != nil {
		return nil, fmt.Errorf("error running MarshalJSON on unstructured object: %w", err)
	}
	ro, _, err := decoder.Decode(b, &gvk, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to decode json data with gvk(%v): %w", gvk.String(), err)
	}
	return ro, nil
}