builder/vmware: output VNC info if headless

/cc @smerrill

builder/vmware/step_run.go

@@ -27,12 +27,20 @@ func (s *stepRun) Run(state map[string]interface{}) multistep.StepAction {
 	driver := state["driver"].(Driver)
 	ui := state["ui"].(packer.Ui)
 	vmxPath := state["vmx_path"].(string)
+	vncPort := state["vnc_port"].(uint)
 
 	// Set the VMX path so that we know we started the machine
 	s.bootTime = time.Now()
 	s.vmxPath = vmxPath
 
 	ui.Say("Starting virtual machine...")
+	if config.Headless {
+		ui.Message(fmt.Sprintf(
+			"The VM will be run headless, without a GUI. If you want to\n"+
+				"view the screen of the VM, connect via VNC without a password to\n"+
+				"127.0.0.1:%d", vncPort))
+	}
+
 	if err := driver.Start(vmxPath, config.Headless); err != nil {
 		err := fmt.Errorf("Error starting VM: %s", err)
 		state["error"] = err