app.js

#!/usr/bin/env node

let http = require('http');
let port = process.env.PORT || 8080;
let Logger = require('./libs/Logger');

global.Logger = Logger;
require('dotenv-safe').config();
let App = require(`./app-${process.env.APP}`);
let server = http.createServer(App);

// Listen on provided port, on all network interfaces.
server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

/**
 * Event listener for HTTP server "error" event.
 */
function onError(error) {
  if (error.syscall !== 'listen') {
    throw error;
  }
  let bind = typeof port === 'string' ? 'Pipe ' + port : 'Port ' + port;
  // handle specific listen errors with friendly messages
  switch (error.code) {
  case 'EACCES':
    Logger.error(bind + ' requires elevated privileges');
    process.exit(1);
    break;
  case 'EADDRINUSE':
    Logger.error(bind + ' is already in use');
    process.exit(1);
    break;
  default:
    throw error;
  }
}

/**
 * Event listener for HTTP server "listening" event.
 */
function onListening() {
  let addr = server.address();
  let bind = typeof addr === 'string' ? 'pipe ' + addr : 'port ' + addr.port;
  Logger.info(`Running ${process.env.APP.toUpperCase()} App on ${bind}`);
}