Fixed some basic client UI issues for the "network" command

Signed-off-by: Madhu Venugopal <madhu@docker.com>

libnetwork/client/client.go

@@ -1,11 +1,9 @@
 package client
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
-	"os"
 	"reflect"
 	"strings"
 
@@ -51,25 +49,21 @@ func (cli *NetworkCli) getMethod(args ...string) (func(string, ...string) error,
 // Cmd is borrowed from Docker UI and acts as the entry point for network UI commands.
 // network UI commands are designed to be invoked from multiple parent chains
 func (cli *NetworkCli) Cmd(chain string, args ...string) error {
-	var errStr string
 	if len(args) > 1 {
 		method, exists := cli.getMethod(args[:2]...)
 		if exists {
-			return method(chain, args[2:]...)
+			return method(chain+" "+args[0], args[2:]...)
 		}
 	}
 	if len(args) > 0 {
 		method, exists := cli.getMethod(args[0])
 		if !exists {
-			errStr = fmt.Sprintf("%s: '%s' is not a %s command. See '%s --help'.\n", chain, args[0], chain, chain)
-			fmt.Fprintf(cli.err, errStr)
-			return errors.New(errStr)
+			return fmt.Errorf("%s: '%s' is not a %s command. See '%s --help'.\n", chain, args[0], chain, chain)
 		}
 		return method(chain, args[1:]...)
 	}
-	errStr = fmt.Sprintf("'%s' is not a valid command. See '%s --help'.\n", chain, chain)
-	fmt.Fprintf(cli.err, errStr)
-	return errors.New(errStr)
+	flag.Usage()
+	return nil
 }
 
 // Subcmd is borrowed from Docker UI and performs the same function of configuring the subCmds
@@ -92,7 +86,6 @@ func (cli *NetworkCli) Subcmd(chain, name, signature, description string, exitOn
 		fmt.Fprintf(cli.out, "\nUsage: %s %s%s%s\n\n%s\n\n", chain, name, options, signature, description)
 		flags.SetOutput(cli.out)
 		flags.PrintDefaults()
-		os.Exit(0)
 	}
 	return flags
 }

libnetwork/client/client_test.go

@@ -28,16 +28,16 @@ func TestClientDummyCommand(t *testing.T) {
 	}
 }
 
-func TestClientNoCommand(t *testing.T) {
+func TestClientNetworkInvalidCommand(t *testing.T) {
 	var out, errOut bytes.Buffer
 	cFunc := func(method, path string, data interface{}, headers map[string][]string) (io.ReadCloser, int, error) {
 		return nopCloser{bytes.NewBufferString("")}, 200, nil
 	}
 	cli := NewNetworkCli(&out, &errOut, cFunc)
 
-	err := cli.Cmd("docker")
+	err := cli.Cmd("docker", "network", "invalid")
 	if err == nil {
-		t.Fatalf("Incorrect Command must fail")
+		t.Fatalf("Passing invalid commands must fail")
 	}
 }
 
@@ -119,33 +119,7 @@ func TestClientNetworkInfo(t *testing.T) {
 	}
 }
 
-func TestClientNetworkJoin(t *testing.T) {
-	var out, errOut bytes.Buffer
-	cFunc := func(method, path string, data interface{}, headers map[string][]string) (io.ReadCloser, int, error) {
-		return nopCloser{bytes.NewBufferString("")}, 200, nil
-	}
-	cli := NewNetworkCli(&out, &errOut, cFunc)
-
-	err := cli.Cmd("docker", "network", "join", "db1", "dbnet", "db1-ep")
-	if err != nil {
-		t.Fatal(err.Error())
-	}
-}
-
-func TestClientNetworkLeave(t *testing.T) {
-	var out, errOut bytes.Buffer
-	cFunc := func(method, path string, data interface{}, headers map[string][]string) (io.ReadCloser, int, error) {
-		return nopCloser{bytes.NewBufferString("")}, 200, nil
-	}
-	cli := NewNetworkCli(&out, &errOut, cFunc)
-
-	err := cli.Cmd("docker", "network", "leave", "db1", "dbnet")
-	if err != nil {
-		t.Fatal(err.Error())
-	}
-}
-
-// Docker Flag processing in flag.go uses os.Exit(0) for --help
+// Docker Flag processing in flag.go uses os.Exit() frequently, even for --help
 // TODO : Handle the --help test-case in the IT when CLI is available
 /*
 func TestClientNetworkCreateHelp(t *testing.T) {

libnetwork/client/network.go

@@ -8,17 +8,57 @@ import (
 	flag "github.com/docker/docker/pkg/mflag"
 )
 
+const (
+	nullNetType = "null"
+)
+
+type command struct {
+	name        string
+	description string
+}
+
+var (
+	networkCommands = []command{
+		{"create", "Create a network"},
+		{"rm", "Remove a network"},
+		{"ls", "List all networks"},
+		{"info", "Display information of a network"},
+	}
+)
+
+func (cli *NetworkCli) CmdNetwork(chain string, args ...string) error {
+	cmd := cli.Subcmd(chain, "network", "COMMAND [OPTIONS] [arg...]", networkUsage(chain), false)
+	cmd.Require(flag.Min, 1)
+	err := cmd.ParseFlags(args, true)
+	if err == nil {
+		cmd.Usage()
+		return fmt.Errorf("Invalid command : %v", args)
+	}
+	return err
+}
+
+func networkUsage(chain string) string {
+	help := "Commands:\n"
+
+	for _, cmd := range networkCommands {
+		help += fmt.Sprintf("    %-10.10s%s\n", cmd.name, cmd.description)
+	}
+
+	help += fmt.Sprintf("\nRun '%s network COMMAND --help' for more information on a command.", chain)
+	return help
+}
+
 // CmdNetworkCreate handles Network Create UI
 func (cli *NetworkCli) CmdNetworkCreate(chain string, args ...string) error {
-	cmd := cli.Subcmd(chain, "create", "NETWORK-NAME", chain+" create", false)
-	flDriver := cmd.String([]string{"d", "-driver"}, "", "Driver to manage the Network")
+	cmd := cli.Subcmd(chain, "create", "NETWORK-NAME", "Creates a new network with a name specified by the user", false)
+	flDriver := cmd.String([]string{"d", "-driver"}, "null", "Driver to manage the Network")
 	cmd.Require(flag.Min, 1)
 	err := cmd.ParseFlags(args, true)
 	if err != nil {
 		return err
 	}
 	if *flDriver == "" {
-		*flDriver = "bridge"
+		*flDriver = nullNetType
 	}
 	// TODO : Proper Backend handling
 	obj, _, err := readBody(cli.call("POST", "/networks/"+args[0], nil, nil))
@@ -34,7 +74,7 @@ func (cli *NetworkCli) CmdNetworkCreate(chain string, args ...string) error {
 
 // CmdNetworkRm handles Network Delete UI
 func (cli *NetworkCli) CmdNetworkRm(chain string, args ...string) error {
-	cmd := cli.Subcmd(chain, "rm", "NETWORK-NAME", chain+" rm", false)
+	cmd := cli.Subcmd(chain, "rm", "NETWORK-NAME", "Deletes a network", false)
 	cmd.Require(flag.Min, 1)
 	err := cmd.ParseFlags(args, true)
 	if err != nil {
@@ -54,7 +94,7 @@ func (cli *NetworkCli) CmdNetworkRm(chain string, args ...string) error {
 
 // CmdNetworkLs handles Network List UI
 func (cli *NetworkCli) CmdNetworkLs(chain string, args ...string) error {
-	cmd := cli.Subcmd(chain, "ls", "", chain+" ls", false)
+	cmd := cli.Subcmd(chain, "ls", "", "Lists all the networks created by the user", false)
 	err := cmd.ParseFlags(args, true)
 	if err != nil {
 		return err
@@ -73,7 +113,7 @@ func (cli *NetworkCli) CmdNetworkLs(chain string, args ...string) error {
 
 // CmdNetworkInfo handles Network Info UI
 func (cli *NetworkCli) CmdNetworkInfo(chain string, args ...string) error {
-	cmd := cli.Subcmd(chain, "info", "NETWORK-NAME", chain+" info", false)
+	cmd := cli.Subcmd(chain, "info", "NETWORK-NAME", "Displays detailed information on a network", false)
 	cmd.Require(flag.Min, 1)
 	err := cmd.ParseFlags(args, true)
 	if err != nil {