worker.js

const amqp = require('amqp-connection-manager')
const {main} = require('./app.js');
const AMQP_URL = process.env.CLOUDAMQP_URL || 'amqp://localhost';
if (!AMQP_URL) process.exit(1)

// GLOBALES
const WORKER_QUEUE = 'worker-queue' 

// RABBITMQ
// Create a new connection manager from AMQP
var connection = amqp.connect([AMQP_URL])
console.log('[AMQP] - Connecting....') 

connection.on('connect', function() {
  process.once('SIGINT', function() { // Close conn on exit
    connection.close()
  })
  return console.log('[AMQP] - Connected!')
})

connection.on('disconnect', function(params) {
  return console.error('[AMQP] - Disconnected.', params.err.stack) 
})

// To receive the execution task messages
let channelWrapper = connection.createChannel({
  json: true,
  setup: function(channel) {
    return Promise.all([
      channel.assertQueue(WORKER_QUEUE, { autoDelete: false, durable: true }),
      channel.prefetch(1),
      channel.consume(WORKER_QUEUE, onMessage)
    ])
  }
})

channelWrapper.waitForConnect()
  .then(function() {
    console.log('[AMQP] - Listening for messages on queue => '+WORKER_QUEUE)
  })
  .catch(function(err) {
    console.error('[AMQP] - Error! ', err)
  })

// Process message from AMQP
function onMessage(data) {
  let message
  try {
    message = JSON.parse(data.content.toString())
  } catch(e) {
    console.error('[AMQP] - Error parsing message... ', data)
  }

  console.log('[AMQP] - Message incoming... ', message)
  channelWrapper.ack(data)
  if (!message) {
    return
  }
  // Actions here
  switch (message.taskName) {
    case 'getNotes': 
      main();
      break

    // case 'other': 
    //   // do another thing....
    //   break

    default:
      console.error('No task was found with name => '+message.taskName)
  }
}