github.com/vieux/docker@v0.6.3-0.20161004191708-e097c2a938c7/cli/command/image/save.go (about)

     1  package image
     2  
     3  import (
     4  	"errors"
     5  	"io"
     6  
     7  	"golang.org/x/net/context"
     8  
     9  	"github.com/docker/docker/cli"
    10  	"github.com/docker/docker/cli/command"
    11  	"github.com/spf13/cobra"
    12  )
    13  
    14  type saveOptions struct {
    15  	images []string
    16  	output string
    17  }
    18  
    19  // NewSaveCommand creates a new `docker save` command
    20  func NewSaveCommand(dockerCli *command.DockerCli) *cobra.Command {
    21  	var opts saveOptions
    22  
    23  	cmd := &cobra.Command{
    24  		Use:   "save [OPTIONS] IMAGE [IMAGE...]",
    25  		Short: "Save one or more images to a tar archive (streamed to STDOUT by default)",
    26  		Args:  cli.RequiresMinArgs(1),
    27  		RunE: func(cmd *cobra.Command, args []string) error {
    28  			opts.images = args
    29  			return runSave(dockerCli, opts)
    30  		},
    31  	}
    32  
    33  	flags := cmd.Flags()
    34  
    35  	flags.StringVarP(&opts.output, "output", "o", "", "Write to a file, instead of STDOUT")
    36  
    37  	return cmd
    38  }
    39  
    40  func runSave(dockerCli *command.DockerCli, opts saveOptions) error {
    41  	if opts.output == "" && dockerCli.Out().IsTerminal() {
    42  		return errors.New("Cowardly refusing to save to a terminal. Use the -o flag or redirect.")
    43  	}
    44  
    45  	responseBody, err := dockerCli.Client().ImageSave(context.Background(), opts.images)
    46  	if err != nil {
    47  		return err
    48  	}
    49  	defer responseBody.Close()
    50  
    51  	if opts.output == "" {
    52  		_, err := io.Copy(dockerCli.Out(), responseBody)
    53  		return err
    54  	}
    55  
    56  	return command.CopyToFile(opts.output, responseBody)
    57  }