README

Rabbitr

RabbitMQ made easy for nodejs

Init / setup

var rabbit = new Rabbitr({
    host: 'localhost',
});

Basic queue usage

// in one module
rabbit.subscribe(['booking.create'], 'sms.send.booking.create', {}, (message) => {
    // send an sms
    message.ack();
});

// in another module
rabbit.subscribe(['booking.create'], 'email.send.booking.create', {}, (message) => {
    // send an email
    message.ack();
});

// elsewhere
rabbit.send('booking.create', {id: 1});

Timers

Rabbitr makes using dead letter exchanges dead easy

// set timer
rabbit.subscribe(['booking.create'], 'booking.not-confirmed.timer.set', {}, (message) => {
  // do something to calculate how long we want the timer to last
    var timeFromNow = 900000; // 15 mins

    rabbit.setTimer('booking.not-confirmed.timer.fire', message.data.id, {
    id: message.data.id,
    }, timeFromNow);

    message.ack();
});

// clear timer if something has happened that means the timer action isn't required
rabbit.subscribe(['booking.confirm'], 'booking.not-confirmed.timer.clear', {}, (message) => {
    rabbit.clearTimer('booking.not-confirmed.timer.fire', message.data.id);

    message.ack();
});

// handle the timer firing
rabbit.subscribe(['booking.not-confirmed.timer.fire'], 'booking.not-confirmed.timer.fire', {}, (message) => {
    // do something off the back of the timer firing
    // in this example, message.data.id is the booking id that wasn't confirmed in time
    message.ack();
});

RPC (remote procedure call)

Use Rabbitr's RPC methods if you need to do something and get a response back, and you want to decouple the two processes via MQ

Make sure you use the same major version of Rabbitr on both the worker and scheduler sides!

Define the worker's method

Use prefetch in the options object to define concurrency (defaults to 1).

rabbit.rpcListener('rpc-test', { prefetch: 5 }, async (message) => {
    // do something with message.data

    await doSomethingAsyncThatMightThrow(message.data);

  return {
    rpc: 'is cool'
    };
});

Calling the worker's RPC

Define the timeout in milliseconds in the options object for rpcExec

rabbit.rpcExec('rpc-test', { some: 'data' }, { timeout: 5000 }).then((response) => {
    // do something with `response`
    // it will look like { rpc: 'is cool' }
});

Debugging

To debug rabbitr, you can enable logging by setting the environment variable DEBUG to "rabbitr".

You can also tell rabbitr to only listen on one or few queues using the environment variable RABBITR_DEBUG. Just set it to a comma-separated list of queues names. RPC queues have the prefix rpc..

# To enable logging
DEBUG=rabbitr node .

# To only listen on rpc channels `user.create` and `user.update`
RABBITR_DEBUG=rpc.user.create,rpc.user.update node .

Usage no npm install needed!