Kadirahq/MUP Deploying to own VM

I have managed to deploy my app using kadirahq/mup but using a VM created from Digital Ocean, Heroku etc? But the problem is that it is public. So my question is how do you deploy to your own VM so it remains private within the clients context and accessible only from within clients firewall. Is it the case of simply changing my working mup.js

But first I need to create my own Docker base image to deploy to? Because I don’t think MUP creates a new docker for you, correct? If so then should be ok to

$docker pull ubuntu-upstart:latest

and use mup.js to point it to, which is usually etc?

module.exports = {

  nodeVersion: "4.4.7",

  servers: {
    one: {
      host: 'IP Address', <---
      username: 'root',
      password: '12345', <---