refactor help func in CLI

Signed-off-by: Victor Vieux <victorvieux@gmail.com>

cli/command/checkpoint/cmd.go

@@ -12,11 +12,8 @@ func NewCheckpointCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "checkpoint",
 		Short: "Manage checkpoints",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
-		Tags: map[string]string{"experimental": "", "version": "1.25"},
+		RunE:  dockerCli.ShowHelp,
+		Tags:  map[string]string{"experimental": "", "version": "1.25"},
 	}
 	cmd.AddCommand(
 		newCreateCommand(dockerCli),

cli/command/cli.go

@@ -20,6 +20,7 @@ import (
 	dopts "github.com/docker/docker/opts"
 	"github.com/docker/go-connections/sockets"
 	"github.com/docker/go-connections/tlsconfig"
+	"github.com/spf13/cobra"
 	"golang.org/x/net/context"
 )
 
@@ -73,6 +74,13 @@ func (cli *DockerCli) In() *InStream {
 	return cli.in
 }
 
+// ShowHelp shows the command help.
+func (cli *DockerCli) ShowHelp(cmd *cobra.Command, args []string) error {
+	cmd.SetOutput(cli.err)
+	cmd.HelpFunc()(cmd, args)
+	return nil
+}
+
 // ConfigFile returns the ConfigFile
 func (cli *DockerCli) ConfigFile() *configfile.ConfigFile {
 	return cli.configFile

cli/command/container/cmd.go

@@ -13,10 +13,7 @@ func NewContainerCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "container",
 		Short: "Manage containers",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		NewAttachCommand(dockerCli),

cli/command/image/cmd.go

@@ -13,10 +13,7 @@ func NewImageCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "image",
 		Short: "Manage images",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		NewBuildCommand(dockerCli),

cli/command/network/cmd.go

@@ -13,10 +13,7 @@ func NewNetworkCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "network",
 		Short: "Manage networks",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		newConnectCommand(dockerCli),

cli/command/node/cmd.go

@@ -14,10 +14,7 @@ func NewNodeCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "node",
 		Short: "Manage Swarm nodes",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		newDemoteCommand(dockerCli),

cli/command/plugin/cmd.go

@@ -12,10 +12,7 @@ func NewPluginCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "plugin",
 		Short: "Manage plugins",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 
 	cmd.AddCommand(

cli/command/secret/cmd.go

@@ -1,8 +1,6 @@
 package secret
 
 import (
-	"fmt"
-
 	"github.com/spf13/cobra"
 
 	"github.com/docker/docker/cli"
@@ -15,9 +13,7 @@ func NewSecretCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "secret",
 		Short: "Manage Docker secrets",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		newSecretListCommand(dockerCli),

cli/command/service/cmd.go

@@ -13,10 +13,7 @@ func NewServiceCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "service",
 		Short: "Manage services",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		newCreateCommand(dockerCli),

cli/command/stack/cmd.go

@@ -12,11 +12,8 @@ func NewStackCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "stack",
 		Short: "Manage Docker stacks",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
-		Tags: map[string]string{"experimental": "", "version": "1.25"},
+		RunE:  dockerCli.ShowHelp,
+		Tags:  map[string]string{"experimental": "", "version": "1.25"},
 	}
 	cmd.AddCommand(
 		newDeployCommand(dockerCli),

cli/command/swarm/cmd.go

@@ -13,10 +13,7 @@ func NewSwarmCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "swarm",
 		Short: "Manage Swarm",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		newInitCommand(dockerCli),

cli/command/system/cmd.go

@@ -13,10 +13,7 @@ func NewSystemCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Use:   "system",
 		Short: "Manage Docker",
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		NewEventsCommand(dockerCli),

cli/command/volume/cmd.go

@@ -14,10 +14,7 @@ func NewVolumeCommand(dockerCli *command.DockerCli) *cobra.Command {
 		Short: "Manage volumes",
 		Long:  volumeDescription,
 		Args:  cli.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-		},
+		RunE:  dockerCli.ShowHelp,
 	}
 	cmd.AddCommand(
 		newCreateCommand(dockerCli),

cmd/docker/docker.go

@@ -34,9 +34,7 @@ func newDockerCommand(dockerCli *command.DockerCli) *cobra.Command {
 				showVersion()
 				return nil
 			}
-			cmd.SetOutput(dockerCli.Err())
-			cmd.HelpFunc()(cmd, args)
-			return nil
+			return dockerCli.ShowHelp(cmd, args)
 		},
 		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
 			// daemon command is special, we redirect directly to another binary