kubernetes/pkg/kubectl/cmd/convert.go

/*
Copyright 2014 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 cmd

import (
	"fmt"
	"io"
	"os"

	"github.com/renstrom/dedent"

	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/unversioned"
	"k8s.io/kubernetes/pkg/apimachinery/registered"
	"k8s.io/kubernetes/pkg/kubectl"
	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
	"k8s.io/kubernetes/pkg/kubectl/resource"
	"k8s.io/kubernetes/pkg/runtime"

	"github.com/spf13/cobra"
)

var (
	convert_long = dedent.Dedent(`
		Convert config files between different API versions. Both YAML
		and JSON formats are accepted.

		The command takes filename, directory, or URL as input, and convert it into format
		of version specified by --output-version flag. If target version is not specified or
		not supported, convert to latest version.

		The default output will be printed to stdout in YAML format. One can use -o option
		to change to output destination.
		`)

	convert_example = dedent.Dedent(`
		# Convert 'pod.yaml' to latest version and print to stdout.
		kubectl convert -f pod.yaml

		# Convert the live state of the resource specified by 'pod.yaml' to the latest version
		# and print to stdout in json format.
		kubectl convert -f pod.yaml --local -o json

		# Convert all files under current directory to latest version and create them all.
		kubectl convert -f . | kubectl create -f -
		`)
)

// NewCmdConvert creates a command object for the generic "convert" action, which
// translates the config file into a given version.
func NewCmdConvert(f *cmdutil.Factory, out io.Writer) *cobra.Command {
	options := &ConvertOptions{}

	cmd := &cobra.Command{
		Use:     "convert -f FILENAME",
		Short:   "Convert config files between different API versions",
		Long:    convert_long,
		Example: convert_example,
		Run: func(cmd *cobra.Command, args []string) {
			err := options.Complete(f, out, cmd, args)
			cmdutil.CheckErr(err)
			err = options.RunConvert()
			cmdutil.CheckErr(err)
		},
	}

	usage := "to need to get converted."
	cmdutil.AddFilenameOptionFlags(cmd, &options.FilenameOptions, usage)
	cmd.MarkFlagRequired("filename")
	cmdutil.AddValidateFlags(cmd)
	cmdutil.AddPrinterFlags(cmd)
	cmd.Flags().BoolVar(&options.local, "local", true, "If true, convert will NOT try to contact api-server but run locally.")
	cmdutil.AddInclude3rdPartyFlags(cmd)
	return cmd
}

// ConvertOptions have the data required to perform the convert operation
type ConvertOptions struct {
	resource.FilenameOptions

	builder *resource.Builder
	local   bool

	encoder runtime.Encoder
	out     io.Writer
	printer kubectl.ResourcePrinter

	outputVersion unversioned.GroupVersion
}

// Complete collects information required to run Convert command from command line.
func (o *ConvertOptions) Complete(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string) (err error) {
	o.outputVersion, err = cmdutil.OutputVersion(cmd, &registered.EnabledVersionsForGroup(api.GroupName)[0])
	if err != nil {
		return err
	}
	if !registered.IsEnabledVersion(o.outputVersion) {
		cmdutil.UsageError(cmd, "'%s' is not a registered version.", o.outputVersion)
	}

	// build the builder
	mapper, typer := f.Object()
	clientMapper := resource.ClientMapperFunc(f.ClientForMapping)

	if o.local {
		fmt.Fprintln(os.Stderr, "running in local mode...")
		o.builder = resource.NewBuilder(mapper, typer, resource.DisabledClientForMapping{ClientMapper: clientMapper}, f.Decoder(true))
	} else {
		o.builder = resource.NewBuilder(mapper, typer, clientMapper, f.Decoder(true))
		schema, err := f.Validator(cmdutil.GetFlagBool(cmd, "validate"), cmdutil.GetFlagString(cmd, "schema-cache-dir"))
		if err != nil {
			return err
		}
		o.builder = o.builder.Schema(schema)
	}
	cmdNamespace, _, err := f.DefaultNamespace()
	if err != nil {
		return err
	}
	o.builder = o.builder.NamespaceParam(cmdNamespace).
		ContinueOnError().
		FilenameParam(false, &o.FilenameOptions).
		Flatten()

	// build the printer
	o.out = out
	outputFormat := cmdutil.GetFlagString(cmd, "output")
	templateFile := cmdutil.GetFlagString(cmd, "template")
	if len(outputFormat) == 0 {
		if len(templateFile) == 0 {
			outputFormat = "yaml"
		} else {
			outputFormat = "template"
		}
	}
	o.encoder = f.JSONEncoder()
	o.printer, _, err = kubectl.GetPrinter(outputFormat, templateFile, false)
	if err != nil {
		return err
	}

	return nil
}

// RunConvert implements the generic Convert command
func (o *ConvertOptions) RunConvert() error {
	r := o.builder.Do()
	err := r.Err()
	if err != nil {
		return err
	}

	count := 0
	err = r.Visit(func(info *resource.Info, err error) error {
		if err != nil {
			return err
		}

		infos := []*resource.Info{info}
		objects, err := resource.AsVersionedObject(infos, false, o.outputVersion, o.encoder)
		if err != nil {
			return err
		}

		count++
		return o.printer.PrintObj(objects, o.out)
	})
	if err != nil {
		return err
	}
	if count == 0 {
		return fmt.Errorf("no objects passed to convert")
	}
	return nil
}