kubernetes/pkg/printers/json.go
Waseem Ahmad 8442a118ea Denote if a printer is generic.
This fixes #38779.

This allows us to avoid case in which printers.GetStandardPrinter
returns nil for both printer and err removing any potential panics that
may arise throughout kubectl commands.

Please see #38779 and #38112 for complete context.

Add comment explaining adding handlers to printers.HumanReadablePrinter
also remove an unnecessary conversion of printers.HumanReadablePrinter
to printers.ResourcePrinter.
2017-05-31 13:02:23 +05:30

110 lines
2.5 KiB
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
}