Enable cross-platforms logout from Registry

Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>

api/client/login.go

@@ -11,7 +11,6 @@ import (
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
 	"github.com/docker/docker/pkg/term"
-	"github.com/docker/docker/registry"
 	"github.com/docker/engine-api/client"
 	"github.com/docker/engine-api/types"
 )
@@ -36,16 +35,7 @@ func (cli *DockerCli) CmdLogin(args ...string) error {
 		cli.in = os.Stdin
 	}
 
-	// The daemon `/info` endpoint informs us of the default registry being
-	// used. This is essential in cross-platforms environment, where for
-	// example a Linux client might be interacting with a Windows daemon, hence
-	// the default registry URL might be Windows specific.
-	serverAddress := registry.IndexServer
-	if info, err := cli.client.Info(); err != nil {
-		fmt.Fprintf(cli.out, "Warning: failed to get default registry endpoint from daemon (%v). Using system default: %s\n", err, serverAddress)
-	} else {
-		serverAddress = info.IndexServerAddress
-	}
+	serverAddress := cli.electAuthServer()
 	if len(cmd.Args()) > 0 {
 		serverAddress = cmd.Arg(0)
 	}

api/client/logout.go

@@ -5,7 +5,6 @@ import (
 
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
-	"github.com/docker/docker/registry"
 )
 
 // CmdLogout logs a user out from a Docker registry.
@@ -14,12 +13,12 @@ import (
 //
 // Usage: docker logout [SERVER]
 func (cli *DockerCli) CmdLogout(args ...string) error {
-	cmd := Cli.Subcmd("logout", []string{"[SERVER]"}, Cli.DockerCommands["logout"].Description+".\nIf no server is specified \""+registry.IndexServer+"\" is the default.", true)
+	cmd := Cli.Subcmd("logout", []string{"[SERVER]"}, Cli.DockerCommands["logout"].Description+".\nIf no server is specified, the default is defined by the daemon.", true)
 	cmd.Require(flag.Max, 1)
 
 	cmd.ParseFlags(args, true)
 
-	serverAddress := registry.IndexServer
+	serverAddress := cli.electAuthServer()
 	if len(cmd.Args()) > 0 {
 		serverAddress = cmd.Arg(0)
 	}

api/client/utils.go

@@ -21,6 +21,20 @@ import (
 	registrytypes "github.com/docker/engine-api/types/registry"
 )
 
+func (cli *DockerCli) electAuthServer() string {
+	// The daemon `/info` endpoint informs us of the default registry being
+	// used. This is essential in cross-platforms environment, where for
+	// example a Linux client might be interacting with a Windows daemon, hence
+	// the default registry URL might be Windows specific.
+	serverAddress := registry.IndexServer
+	if info, err := cli.client.Info(); err != nil {
+		fmt.Fprintf(cli.out, "Warning: failed to get default registry endpoint from daemon (%v). Using system default: %s\n", err, serverAddress)
+	} else {
+		serverAddress = info.IndexServerAddress
+	}
+	return serverAddress
+}
+
 // encodeAuthToBase64 serializes the auth configuration as JSON base64 payload
 func encodeAuthToBase64(authConfig types.AuthConfig) (string, error) {
 	buf, err := json.Marshal(authConfig)