index.js

var rabbitmqUri = process.env.MQ_URL || "amqp://notification-mq";
var smtpUri = process.env.MAIL_URL;
var simulate = process.env.SIMULATE === "true" || false;
var amqp = require("amqplib/callback_api");
var nodemailer = require("nodemailer");
var transporter = nodemailer.createTransport(smtpUri);

function sendMail(subject, message) {
  var sendingAddress = process.env.TO_ADDRESS;
  var mailOptions = {
    to: sendingAddress,
    subject: subject,
    text: message,
  };
  if (simulate) {
    console.log(
      "Simulated sending of message. Subject: %s, Text: %s, Address: %s",
      mailOptions.subject,
      mailOptions.text,
      mailOptions.to
    );
  } else {
    transporter.sendMail(mailOptions, function (error, info) {
      if (error) {
        return console.log(error);
      }
      console.log("Message %s sent: %s", info.messageId, info.response);
    });
  }
}

amqp.connect(rabbitmqUri, function (err, conn) {
  conn.createChannel(
    function (err, ch) {
      var queue = "notifications";
      ch.assertQueue(queue, { durable: false });
      console.log(
        " [*] Waiting for messages in %s. To exit press CTRL+C",
        queue
      );
      ch.consume(queue, function (msg) {
        var message = JSON.parse(msg.content);
        console.log(message);
        sendMail(
          "Notification!",
          "Hi, here's a new notification: " + message.text
        );
      });
    },
    { noAck: true }
  );
});