Inroduce SWARM --data-path-addr flag

This new flag will allow the configuration of an interface that
can be used for data path traffic to be isolated from control
plane traffic. This flag is simply percolated down to libnetwork
and will be used by all the global scope drivers (today overlay)

Negative test added for invalid flag arguments

Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>

cli/command/swarm/init.go

@@ -19,6 +19,7 @@ type initOptions struct {
 	listenAddr NodeAddrOption
 	// Not a NodeAddrOption because it has no default port.
 	advertiseAddr   string
+	dataPathAddr    string
 	forceNewCluster bool
 	availability    string
 }
@@ -40,6 +41,7 @@ func newInitCommand(dockerCli command.Cli) *cobra.Command {
 	flags := cmd.Flags()
 	flags.Var(&opts.listenAddr, flagListenAddr, "Listen address (format: <ip|interface>[:port])")
 	flags.StringVar(&opts.advertiseAddr, flagAdvertiseAddr, "", "Advertised address (format: <ip|interface>[:port])")
+	flags.StringVar(&opts.dataPathAddr, flagDataPathAddr, "", "Address or interface to use for data path traffic (format: <ip|interface>)")
 	flags.BoolVar(&opts.forceNewCluster, "force-new-cluster", false, "Force create a new cluster from current state")
 	flags.BoolVar(&opts.autolock, flagAutolock, false, "Enable manager autolocking (requiring an unlock key to start a stopped manager)")
 	flags.StringVar(&opts.availability, flagAvailability, "active", `Availability of the node ("active"|"pause"|"drain")`)
@@ -54,6 +56,7 @@ func runInit(dockerCli command.Cli, flags *pflag.FlagSet, opts initOptions) erro
 	req := swarm.InitRequest{
 		ListenAddr:       opts.listenAddr.String(),
 		AdvertiseAddr:    opts.advertiseAddr,
+		DataPathAddr:     opts.dataPathAddr,
 		ForceNewCluster:  opts.forceNewCluster,
 		Spec:             opts.swarmOptions.ToSpec(flags),
 		AutoLockManagers: opts.swarmOptions.autolock,

cli/command/swarm/join.go

@@ -19,6 +19,7 @@ type joinOptions struct {
 	listenAddr NodeAddrOption
 	// Not a NodeAddrOption because it has no default port.
 	advertiseAddr string
+	dataPathAddr  string
 	token         string
 	availability  string
 }
@@ -41,6 +42,7 @@ func newJoinCommand(dockerCli command.Cli) *cobra.Command {
 	flags := cmd.Flags()
 	flags.Var(&opts.listenAddr, flagListenAddr, "Listen address (format: <ip|interface>[:port])")
 	flags.StringVar(&opts.advertiseAddr, flagAdvertiseAddr, "", "Advertised address (format: <ip|interface>[:port])")
+	flags.StringVar(&opts.dataPathAddr, flagDataPathAddr, "", "Address or interface to use for data path traffic (format: <ip|interface>)")
 	flags.StringVar(&opts.token, flagToken, "", "Token for entry into the swarm")
 	flags.StringVar(&opts.availability, flagAvailability, "active", `Availability of the node ("active"|"pause"|"drain")`)
 	return cmd
@@ -54,6 +56,7 @@ func runJoin(dockerCli command.Cli, flags *pflag.FlagSet, opts joinOptions) erro
 		JoinToken:     opts.token,
 		ListenAddr:    opts.listenAddr.String(),
 		AdvertiseAddr: opts.advertiseAddr,
+		DataPathAddr:  opts.dataPathAddr,
 		RemoteAddrs:   []string{opts.remote},
 	}
 	if flags.Changed(flagAvailability) {

cli/command/swarm/opts.go

@@ -21,6 +21,7 @@ const (
 	flagDispatcherHeartbeat = "dispatcher-heartbeat"
 	flagListenAddr          = "listen-addr"
 	flagAdvertiseAddr       = "advertise-addr"
+	flagDataPathAddr        = "data-path-addr"
 	flagQuiet               = "quiet"
 	flagRotate              = "rotate"
 	flagToken               = "token"