@@ -17,6 +17,7 @@ func NewCheckpointCommand(dockerCli *command.DockerCli) *cobra.Command {

 		Run: func(cmd *cobra.Command, args []string) {

 			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())

 		},

+		Tags: map[string]string{"experimental": ""},

 	}

 	cmd.AddCommand(

 		newCreateCommand(dockerCli),

@@ -32,27 +32,21 @@ type Streams interface {

 // DockerCli represents the docker command line client.

 // Instances of the client can be returned from NewDockerCli.

 type DockerCli struct {

-	configFile      *configfile.ConfigFile

-	in              *InStream

-	out             *OutStream

-	err             io.Writer

-	keyFile         string

-	client          client.APIClient

-	hasExperimental *bool

+	configFile *configfile.ConfigFile

+	in         *InStream

+	out        *OutStream

+	err        io.Writer

+	keyFile    string

+	client     client.APIClient

 }

 // HasExperimental returns true if experimental features are accessible

 func (cli *DockerCli) HasExperimental() bool {

-	if cli.hasExperimental == nil {

-		if cli.client == nil {

-			cli.Initialize(cliflags.NewClientOptions())

-		}

-		enabled := false

-		cli.hasExperimental = &enabled

-		enabled, _ = cli.client.Ping(context.Background())

+	if cli.client == nil {

+		return false

 	}

-

-	return *cli.hasExperimental

+	enabled, _ := cli.client.Ping(context.Background())

+	return enabled

 }

 // Client returns the APIClient

@@ -70,17 +70,12 @@ func AddCommands(cmd *cobra.Command, dockerCli *command.DockerCli) {

 		hide(image.NewSaveCommand(dockerCli)),

 		hide(image.NewTagCommand(dockerCli)),

 		hide(system.NewInspectCommand(dockerCli)),

+		stack.NewStackCommand(dockerCli),

+		stack.NewTopLevelDeployCommand(dockerCli),

+		checkpoint.NewCheckpointCommand(dockerCli),

+		plugin.NewPluginCommand(dockerCli),

 	)

-	if dockerCli.HasExperimental() {

-		cmd.AddCommand(

-			stack.NewStackCommand(dockerCli),

-			stack.NewTopLevelDeployCommand(dockerCli),

-			checkpoint.NewCheckpointCommand(dockerCli),

-			plugin.NewPluginCommand(dockerCli),

-		)

-	}

-

 }

 func hide(cmd *cobra.Command) *cobra.Command {

@@ -45,11 +45,10 @@ func NewStartCommand(dockerCli *command.DockerCli) *cobra.Command {

 	flags.BoolVarP(&opts.openStdin, "interactive", "i", false, "Attach container's STDIN")

 	flags.StringVar(&opts.detachKeys, "detach-keys", "", "Override the key sequence for detaching a container")

-	if dockerCli.HasExperimental() {

-		flags.StringVar(&opts.checkpoint, "checkpoint", "", "Restore from this checkpoint")

-		flags.StringVar(&opts.checkpointDir, "checkpoint-dir", "", "Use a custom checkpoint storage directory")

-	}

-

+	flags.StringVar(&opts.checkpoint, "checkpoint", "", "Restore from this checkpoint")

+	flags.SetAnnotation("checkpoint", "experimental", nil)

+	flags.StringVar(&opts.checkpointDir, "checkpoint-dir", "", "Use a custom checkpoint storage directory")

+	flags.SetAnnotation("checkpoint-dir", "experimental", nil)

 	return cmd

 }

@@ -111,9 +111,8 @@ func NewBuildCommand(dockerCli *command.DockerCli) *cobra.Command {

 	command.AddTrustedFlags(flags, true)

-	if dockerCli.HasExperimental() {

-		flags.BoolVar(&options.squash, "squash", false, "Squash newly built layers into a single new layer")

-	}

+	flags.BoolVar(&options.squash, "squash", false, "Squash newly built layers into a single new layer")

+	flags.SetAnnotation("squash", "experimental", nil)

 	return cmd

 }

@@ -17,6 +17,7 @@ func NewPluginCommand(dockerCli *command.DockerCli) *cobra.Command {

 		Run: func(cmd *cobra.Command, args []string) {

 			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())

 		},

+		Tags: map[string]string{"experimental": ""},

 	}

 	cmd.AddCommand(

@@ -17,6 +17,7 @@ func NewStackCommand(dockerCli *command.DockerCli) *cobra.Command {

 		Run: func(cmd *cobra.Command, args []string) {

 			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())

 		},

+		Tags: map[string]string{"experimental": ""},

 	}

 	cmd.AddCommand(

 		newConfigCommand(dockerCli),

@@ -36,6 +36,7 @@ func newDeployCommand(dockerCli *command.DockerCli) *cobra.Command {

 			opts.namespace = strings.TrimSuffix(args[0], ".dab")

 			return runDeploy(dockerCli, opts)

 		},

+		Tags: map[string]string{"experimental": ""},

 	}

 	flags := cmd.Flags()

@@ -33,7 +33,8 @@ func newDockerCommand(dockerCli *command.DockerCli) *cobra.Command {

 				showVersion()

 				return nil

 			}

-			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())

+			cmd.SetOutput(dockerCli.Err())

+			cmd.HelpFunc()(cmd, args)

 			return nil

 		},

 		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {

@@ -45,6 +46,22 @@ func newDockerCommand(dockerCli *command.DockerCli) *cobra.Command {

 	}

 	cli.SetupRootCommand(cmd)

+	cmd.SetHelpFunc(func(ccmd *cobra.Command, args []string) {

+		var err error

+		if dockerCli.Client() == nil {

+			// flags must be the top-level command flags, not cmd.Flags()

+			opts.Common.SetDefaultOptions(flags)

+			dockerPreRun(opts)

+			err = dockerCli.Initialize(opts)

+		}

+		if err != nil || !dockerCli.HasExperimental() {

+			hideExperimentalFeatures(ccmd)

+		}

+		if err := ccmd.Help(); err != nil {

+			ccmd.Println(err)

+		}

+	})

+

 	flags = cmd.Flags()

 	flags.BoolVarP(&opts.Version, "version", "v", false, "Print version information and quit")

 	flags.StringVar(&opts.ConfigDir, "config", cliconfig.ConfigDir(), "Location of client config files")

@@ -105,3 +122,19 @@ func dockerPreRun(opts *cliflags.ClientOptions) {

 		utils.EnableDebug()

 	}

 }

+

+func hideExperimentalFeatures(cmd *cobra.Command) {

+	// hide flags

+	cmd.Flags().VisitAll(func(f *pflag.Flag) {

+		if _, ok := f.Annotations["experimental"]; ok {

+			f.Hidden = true

+		}

+	})

+

+	for _, subcmd := range cmd.Commands() {

+		// hide subcommands

+		if _, ok := subcmd.Tags["experimental"]; ok {

+			subcmd.Hidden = true

+		}

+	}

+}

@@ -123,7 +123,7 @@ github.com/matttproud/golang_protobuf_extensions fc2b8d3a73c4867e51861bbdd5ae3c1

 github.com/pkg/errors 01fa4104b9c248c8945d14d9f128454d5b28d595

 # cli

-github.com/spf13/cobra v1.4.1 https://github.com/dnephin/cobra.git

+github.com/spf13/cobra v1.5 https://github.com/dnephin/cobra.git

 github.com/spf13/pflag dabebe21bf790f782ea4c7bbd2efc430de182afd

 github.com/inconshreveable/mousetrap 76626ae9c91c4f2a10f34cad8ce83ea42c93bb75

 github.com/flynn-archive/go-shlex 3f9db97f856818214da2e1057f8ad84803971cff

@@ -59,6 +59,9 @@ type Command struct {

 	Deprecated string

 	// Is this command hidden and should NOT show up in the list of available commands?

 	Hidden bool

+	// Tags are key/value pairs that can be used by applications to identify or

+	// group commands

+	Tags map[string]string

 	// Full set of flags

 	flags *flag.FlagSet

 	// Set of flags childrens of this command will inherit

@@ -111,10 +114,10 @@ type Command struct {

 	flagErrorBuf *bytes.Buffer

-	args          []string                 // actual args parsed from flags

-	output        *io.Writer               // nil means stderr; use Out() method instead

-	usageFunc     func(*Command) error     // Usage can be defined by application

-	usageTemplate string                   // Can be defined by Application

+	args          []string             // actual args parsed from flags

+	output        *io.Writer           // nil means stderr; use Out() method instead

+	usageFunc     func(*Command) error // Usage can be defined by application

+	usageTemplate string               // Can be defined by Application

 	flagErrorFunc func(*Command, error) error

 	helpTemplate  string                   // Can be defined by Application

 	helpFunc      func(*Command, []string) // Help can be defined by application

@@ -417,7 +420,7 @@ func argsMinusFirstX(args []string, x string) []string {

 func isFlagArg(arg string) bool {

 	return ((len(arg) >= 3 && arg[1] == '-') ||

-	        (len(arg) >= 2 && arg[0] == '-' && arg[1] != '-'))

+		(len(arg) >= 2 && arg[0] == '-' && arg[1] != '-'))

 }

 // Find the target command given the args and command tree

@@ -820,7 +823,7 @@ func (c commandSorterByName) Less(i, j int) bool { return c[i].Name() < c[j].Nam

 // Commands returns a sorted slice of child commands.

 func (c *Command) Commands() []*Command {

 	// do not sort commands if it already sorted or sorting was disabled

-	if EnableCommandSorting && !c.commandsAreSorted{

+	if EnableCommandSorting && !c.commandsAreSorted {

 		sort.Sort(commandSorterByName(c.commands))

 		c.commandsAreSorted = true

 	}