package image import ( "io" "github.com/docker/docker/cli" "github.com/docker/docker/cli/command" "github.com/pkg/errors" "github.com/spf13/cobra" "golang.org/x/net/context" ) type saveOptions struct { images []string output string } // NewSaveCommand creates a new `docker save` command func NewSaveCommand(dockerCli *command.DockerCli) *cobra.Command { var opts saveOptions cmd := &cobra.Command{ Use: "save [OPTIONS] IMAGE [IMAGE...]", Short: "Save one or more images to a tar archive (streamed to STDOUT by default)", Args: cli.RequiresMinArgs(1), RunE: func(cmd *cobra.Command, args []string) error { opts.images = args return runSave(dockerCli, opts) }, } flags := cmd.Flags() flags.StringVarP(&opts.output, "output", "o", "", "Write to a file, instead of STDOUT") return cmd } func runSave(dockerCli *command.DockerCli, opts saveOptions) error { if opts.output == "" && dockerCli.Out().IsTerminal() { return errors.New("Cowardly refusing to save to a terminal. Use the -o flag or redirect.") } responseBody, err := dockerCli.Client().ImageSave(context.Background(), opts.images) if err != nil { return err } defer responseBody.Close() if opts.output == "" { _, err := io.Copy(dockerCli.Out(), responseBody) return err } return command.CopyToFile(opts.output, responseBody) }