Merge pull request moby#23267 from vdemeester/migrate-export-to-cobra

Use spf13/cobra for docker export

api/client/commands.go

@@ -10,7 +10,6 @@ func (cli *DockerCli) Command(name string) func(...string) error {
 		"diff":               cli.CmdDiff,
 		"events":             cli.CmdEvents,
 		"exec":               cli.CmdExec,
-		"export":             cli.CmdExport,
 		"history":            cli.CmdHistory,
 		"images":             cli.CmdImages,
 		"import":             cli.CmdImport,

api/client/container/export.go

@@ -0,0 +1,59 @@
+package container
+
+import (
+	"errors"
+	"io"
+
+	"golang.org/x/net/context"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+)
+
+type exportOptions struct {
+	container string
+	output    string
+}
+
+// NewExportCommand creates a new `docker export` command
+func NewExportCommand(dockerCli *client.DockerCli) *cobra.Command {
+	var opts exportOptions
+
+	cmd := &cobra.Command{
+		Use:   "export [OPTIONS] CONTAINER",
+		Short: "Export a container's filesystem as a tar archive",
+		Args:  cli.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			opts.container = args[0]
+			return runExport(dockerCli, opts)
+		},
+	}
+
+	flags := cmd.Flags()
+
+	flags.StringVarP(&opts.output, "output", "o", "", "Write to a file, instead of STDOUT")
+
+	return cmd
+}
+
+func runExport(dockerCli *client.DockerCli, opts exportOptions) error {
+	if opts.output == "" && dockerCli.IsTerminalOut() {
+		return errors.New("Cowardly refusing to save to a terminal. Use the -o flag or redirect.")
+	}
+
+	clnt := dockerCli.Client()
+
+	responseBody, err := clnt.ContainerExport(context.Background(), opts.container)
+	if err != nil {
+		return err
+	}
+	defer responseBody.Close()
+
+	if opts.output == "" {
+		_, err := io.Copy(dockerCli.Out(), responseBody)
+		return err
+	}
+
+	return client.CopyToFile(opts.output, responseBody)
+}

api/client/save.go

@@ -37,6 +37,6 @@ func (cli *DockerCli) CmdSave(args ...string) error {
 		return err
 	}
 
-	return copyToFile(*outfile, responseBody)
+	return CopyToFile(*outfile, responseBody)
 
 }

api/client/utils.go

@@ -162,7 +162,8 @@ func (cli *DockerCli) GetTtySize() (int, int) {
 	return int(ws.Height), int(ws.Width)
 }
 
-func copyToFile(outfile string, r io.Reader) error {
+// CopyToFile writes the content of the reader to the specifed file
+func CopyToFile(outfile string, r io.Reader) error {
 	tmpFile, err := ioutil.TempFile(filepath.Dir(outfile), ".docker_temp_")
 	if err != nil {
 		return err

cli/cobraadaptor/adaptor.go

@@ -34,6 +34,7 @@ func NewCobraAdaptor(clientFlags *cliflags.ClientFlags) CobraAdaptor {
 	rootCmd.SetOutput(stdout)
 	rootCmd.AddCommand(
 		container.NewCreateCommand(dockerCli),
+		container.NewExportCommand(dockerCli),
 		container.NewRunCommand(dockerCli),
 		image.NewSearchCommand(dockerCli),
 		volume.NewVolumeCommand(dockerCli),

cli/usage.go

@@ -15,7 +15,6 @@ var DockerCommandUsage = []Command{
 	{"diff", "Inspect changes on a container's filesystem"},
 	{"events", "Get real time events from the server"},
 	{"exec", "Run a command in a running container"},
-	{"export", "Export a container's filesystem as a tar archive"},
 	{"history", "Show the history of an image"},
 	{"images", "List images"},
 	{"import", "Import the contents from a tarball to create a filesystem image"},