index.js is a single-file app that either sends a timestamp every 1.5 seconds to the queue or reads from the queue depending on the invocation argument. The queue location is defined by the QUEUE_HOST environment variable:

'use strict'

const Queue = require('bull');

const veryImportantThingsQueue = new Queue('very_important_things',
                                           { redis: { port: 6379,
                                                      host: process.env.QUEUE_HOST }});

// Prints any message data received
class Receiver {
    constructor () {
        console.info('Registering listener...');
        veryImportantThingsQueue.process(job => {
            console.info('Got a message from the queue with data:', job.data);
            return Promise.resolve({});
        });
    }
}

// Sends the date every 1.5 seconds
class Sender {
    constructor () {
        function sendMessage() {
            const messageValue = new Date();
            console.info('Sending a message...', messageValue);
            veryImportantThingsQueue.add({ 'key': messageValue });
        }

        setInterval(sendMessage, 1500);
    }
}

// Sanity check
if (process.argv.length < 2) {
    throw new Error(`Usage: ${process.argv.slice(2).join(' ')} <sender | receiver>`);
}


// Start either receiver or sender depending of CLI arg
console.info('Starting...');
if (process.argv[2] === 'sender') {
    new Sender();
} else if (process.argv[2] === 'receiver') {
    new Receiver();
} else {
    throw new Error(`Usage: ${process.argv.slice(0, 2).join(' ')} <sender | receiver>`);
}