@@ -343,7 +343,7 @@ func populateCommand(c *Container, env []string) error {

 	case "none":

 	case "host":

 		en.HostNetworking = true

-	case "bridge":

+	case "bridge", "": // empty string to support existing containers

 		if !c.Config.NetworkDisabled {

 			network := c.NetworkSettings

 			en.Interface = &execdriver.NetworkInterface{

@@ -503,9 +503,18 @@ func (container *Container) StderrLogPipe() io.ReadCloser {

 	return utils.NewBufReader(reader)

 }

-func (container *Container) buildHostnameAndHostsFiles(IP string) {

+func (container *Container) buildHostname() {

 	container.HostnamePath = path.Join(container.root, "hostname")

-	ioutil.WriteFile(container.HostnamePath, []byte(container.Config.Hostname+"\n"), 0644)

+

+	if container.Config.Domainname != "" {

+		ioutil.WriteFile(container.HostnamePath, []byte(fmt.Sprintf("%s.%s\n", container.Config.Hostname, container.Config.Domainname)), 0644)

+	} else {

+		ioutil.WriteFile(container.HostnamePath, []byte(container.Config.Hostname+"\n"), 0644)

+	}

+}

+

+func (container *Container) buildHostnameAndHostsFiles(IP string) {

+	container.buildHostname()

 	hostsContent := []byte(`

 127.0.0.1	localhost

@@ -523,12 +532,11 @@ ff02::2		ip6-allrouters

 	} else if !container.Config.NetworkDisabled {

 		hostsContent = append([]byte(fmt.Sprintf("%s\t%s\n", IP, container.Config.Hostname)), hostsContent...)

 	}

-

 	ioutil.WriteFile(container.HostsPath, hostsContent, 0644)

 }

 func (container *Container) allocateNetwork() error {

-	if container.Config.NetworkDisabled {

+	if container.Config.NetworkDisabled || container.hostConfig.NetworkMode == "host" {

 		return nil

 	}

@@ -981,14 +989,22 @@ func (container *Container) setupContainerDns() error {

 	if container.ResolvConfPath != "" {

 		return nil

 	}

+

 	var (

 		config = container.hostConfig

 		daemon = container.daemon

 	)

+

+	if config.NetworkMode == "host" {

+		container.ResolvConfPath = "/etc/resolv.conf"

+		return nil

+	}

+

 	resolvConf, err := utils.GetResolvConf()

 	if err != nil {

 		return err

 	}

+

 	// If custom dns exists, then create a resolv.conf for the container

 	if len(config.Dns) > 0 || len(daemon.config.Dns) > 0 || len(config.DnsSearch) > 0 || len(daemon.config.DnsSearch) > 0 {

 		var (

@@ -1028,7 +1044,22 @@ func (container *Container) setupContainerDns() error {

 }

 func (container *Container) initializeNetworking() error {

-	if container.daemon.config.DisableNetwork {

+	var err error

+	if container.hostConfig.NetworkMode == "host" {

+		container.Config.Hostname, err = os.Hostname()

+		if err != nil {

+			return err

+		}

+

+		parts := strings.SplitN(container.Config.Hostname, ".", 2)

+		if len(parts) > 1 {

+			container.Config.Hostname = parts[0]

+			container.Config.Domainname = parts[1]

+		}

+		container.HostsPath = "/etc/hosts"

+

+		container.buildHostname()

+	} else if container.daemon.config.DisableNetwork {

 		container.Config.NetworkDisabled = true

 		container.buildHostnameAndHostsFiles("127.0.1.1")

 	} else {

@@ -22,33 +22,3 @@ func TestParseLxcConfOpt(t *testing.T) {

 		}

 	}

 }

-

-func TestParseNetMode(t *testing.T) {

-	testFlags := []struct {

-		flag      string

-		mode      string

-		container string

-		err       bool

-	}{

-		{"", "", "", true},

-		{"bridge", "bridge", "", false},

-		{"disable", "disable", "", false},

-		{"container:foo", "container", "foo", false},

-		{"container:", "", "", true},

-		{"container", "", "", true},

-		{"unknown", "", "", true},

-	}

-

-	for _, to := range testFlags {

-		mode, err := parseNetMode(to.flag)

-		if mode != to.mode {

-			t.Fatalf("-net %s: expected net mode: %q, got: %q", to.flag, to.mode, mode)

-		}

-		if container != to.container {

-			t.Fatalf("-net %s: expected net container: %q, got: %q", to.flag, to.container, container)

-		}

-		if (err != nil) != to.err {

-			t.Fatal("-net %s: expected an error got none", to.flag)

-		}

-	}

-}