json.go

/*
Copyright 2017 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 printers

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"

	"k8s.io/apimachinery/pkg/runtime"

	"github.com/ghodss/yaml"
)

// JSONPrinter is an implementation of ResourcePrinter which outputs an object as JSON.
type JSONPrinter struct {
}

func (p *JSONPrinter) AfterPrint(w io.Writer, res string) error {
	return nil
}

// PrintObj is an implementation of ResourcePrinter.PrintObj which simply writes the object to the Writer.
func (p *JSONPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
	switch obj := obj.(type) {
	case *runtime.Unknown:
		var buf bytes.Buffer
		err := json.Indent(&buf, obj.Raw, "", "    ")
		if err != nil {
			return err
		}
		buf.WriteRune('\n')
		_, err = buf.WriteTo(w)
		return err
	}

	data, err := json.MarshalIndent(obj, "", "    ")
	if err != nil {
		return err
	}
	data = append(data, '\n')
	_, err = w.Write(data)
	return err
}

// TODO: implement HandledResources()
func (p *JSONPrinter) HandledResources() []string {
	return []string{}
}

func (p *JSONPrinter) IsGeneric() bool {
	return true
}

// YAMLPrinter is an implementation of ResourcePrinter which outputs an object as YAML.
// The input object is assumed to be in the internal version of an API and is converted
// to the given version first.
type YAMLPrinter struct {
	version   string
	converter runtime.ObjectConvertor
}

func (p *YAMLPrinter) AfterPrint(w io.Writer, res string) error {
	return nil
}

// PrintObj prints the data as YAML.
func (p *YAMLPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
	switch obj := obj.(type) {
	case *runtime.Unknown:
		data, err := yaml.JSONToYAML(obj.Raw)
		if err != nil {
			return err
		}
		_, err = w.Write(data)
		return err
	}

	output, err := yaml.Marshal(obj)
	if err != nil {
		return err
	}
	_, err = fmt.Fprint(w, string(output))
	return err
}

// TODO: implement HandledResources()
func (p *YAMLPrinter) HandledResources() []string {
	return []string{}
}

func (p *YAMLPrinter) IsGeneric() bool {
	return true
}