azk deploy with multiple enviroments

Azkfile.js

/**
 * Documentation: http://docs.azk.io/Azkfile.js
 */

var name    = "app";
var ENV     = env.DEPLOY_ENV || "stage";
var PATH    = name + "-" + ENV;
var project = (ENV == "prod") ? name : name + "-" + ENV;

var host = (function() {
  var prefix = (ENV == "prod") ? "app" : (name + "-" + ENV);
  return prefix + "." + domain;
})();

var HOST_DOMAIN = env.HOST_DOMAIN || host;

// Adds the systems that shape your system
systems({
  /* DEVELOPMENT */
  'app': {
    // ...
    http: {
      domains: [
        "#{system.name}.#{azk.default_domain}",
        HOST_DOMAIN,
        "#{env.HOST_IP}",
      ]
    },
  },
  postgres: {
    // ...
  },

  /* Deploy */
  // to deploy in STAGE run: `azk deploy`
  // to deploy in PROD run: `DEPLOY_ENV=prod azk deploy`
  deploy: {
    image: {"docker": "azukiapp/deploy-digitalocean:0.0.2"},
    mounts: {
      "/azk/deploy/src"    : path("."),
      "/azk/deploy/.ssh"   : path("#{env.HOME}/.ssh"),
      "/azk/deploy/.config": persistent("deploy-config"),
    },
    scalable: {"default": 0, "limit": 0},
    envs: {
      // BOX_NAME                 : BOX_NAME,
      BOX_BACKUP               : true,
      REMOTE_PROJECT_PATH_ID   : project,
      HOST_DOMAIN              : host,
      AZK_ENV                  : ENV,
    },
  },
});