fix up

builder/qemu/builder.go

@@ -105,6 +105,7 @@ type Config struct {
 	ShutdownCommand string     `mapstructure:"shutdown_command"`
 	SSHHostPortMin  uint       `mapstructure:"ssh_host_port_min"`
 	SSHHostPortMax  uint       `mapstructure:"ssh_host_port_max"`
+	VncIP		string	   `mapstructure:"vnc_ip"`
 	VNCPortMin      uint       `mapstructure:"vnc_port_min"`
 	VNCPortMax      uint       `mapstructure:"vnc_port_max"`
 	VMName          string     `mapstructure:"vm_name"`
@@ -354,10 +355,15 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
 				"a checksum is highly recommended.")
 	}
 
+	if b.config.VncIP == "" {
+		warnings = append(warnings,
+			"No VNC IP address specified, will default to 127.0.0.1")
+		b.config.VncIP = "127.0.0.1"
+        }
+          
 	if errs != nil && len(errs.Errors) > 0 {
 		return warnings, errs
 	}
-
 	return warnings, nil
 }
 

builder/qemu/step_type_boot_command.go

@@ -40,10 +40,12 @@ func (s *stepTypeBootCommand) Run(state multistep.StateBag) multistep.StepAction
 	httpPort := state.Get("http_port").(uint)
 	ui := state.Get("ui").(packer.Ui)
 	vncPort := state.Get("vnc_port").(uint)
+	vncAddr := state.Get("vnc_ip").(string)
 
 	// Connect to VNC
 	ui.Say("Connecting to VM via VNC")
-	nc, err := net.Dial("tcp", fmt.Sprintf("127.0.0.1:%d", vncPort))
+        // tbh why is this hardcoded anyway?
+	nc, err := net.Dial("tcp", fmt.Sprintf("%s:%d", vncAddr, vncPort))
 	if err != nil {
 		err := fmt.Errorf("Error connecting to VNC: %s", err)
 		state.Put("error", err)