Scheduling messages with RabbitMQ, using the rabbitmq_delayed_message_exchange plugin and amqplib in NodeJS

amqplib-delayed-message.js

/**
 * Install and enable the rabbitmq_delayed_message_exchange plugin as described by Alvaro Videla in this blogpost:
 * https://www.rabbitmq.com/blog/2015/04/16/scheduling-messages-with-rabbitmq/
 */
const amqp = require('amqplib');
const exchange = 'yourExchangeName';
const queue = 'yourQueueName';
const queueBinding = 'yourQueueBindingName';

// Message consumer
amqp
  .connect('amqp://localhost')
  .then(conn => conn.createChannel())
  .then(ch => {
    // Assert a x-delayed-message Exchange. The type of the exchange is specified in the arguments as "x-delayed-type"
    ch.assertExchange(exchange, 'x-delayed-message', { durable: true, arguments: { 'x-delayed-type': 'direct' } });
    return ch
      .assertQueue(queue, { durable: true })
      .then(() => ch.bindQueue(queue, exchange, queueBinding))
      .then(() => {
        ch.consume(queue, (msg) => {
          // Handle delayed message
          // ...
        }, { noAck: true });
      });
  });

// Publish message
amqp
  .connect('amqp://localhost')
  .then(conn => conn.createChannel())
  .then(ch => {
    // Publish message with a delay of 500 ms
    const headers = { 'x-delay': 500 };
    ch.publish(exchange, queueBinding, new Buffer('hello world'), { headers });
  });