pkg/util/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"
)

// LoadResourceFromYaml loads a k8s resource from a yaml definition
func LoadResourceFromYaml(scheme *runtime.Scheme, data string) (runtime.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
	}
	return RuntimeObjectFromUnstructured(scheme, &u)
}

// LoadRawResourceFromYaml loads a k8s resource from a yaml definition without making assumptions on the underlying type
func LoadRawResourceFromYaml(data string) (runtime.Object, error) {
	source := []byte(data)
	jsonSource, err := yaml.ToJSON(source)
	if err != nil {
		return nil, err
	}
	var objmap map[string]interface{}
	if err = json.Unmarshal(jsonSource, &objmap); err != nil {
		return nil, err
	}
	return &unstructured.Unstructured{
		Object: objmap,
	}, nil
}

// RuntimeObjectFromUnstructured converts an unstructured to a runtime object
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: %v", err)
	}
	ro, _, err := decoder.Decode(b, &gvk, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to decode json data with gvk(%v): %v", gvk.String(), err)
	}
	return ro, nil
}