Roger Rabbit

Roger Rabbit is a module that makes the process of consuming and publishing messages in message brokers easier. It is a wrapper for amqplib.

Install

npm install @klicksite/roger-rabbit --save

Documentation

Broker

Broker expect to receives a rabbitMQ connection string and broker options. Example:

// broker.js
const Broker = require('roger-rabbit');

const broker = new Broker('amqp://guest:guest@localhost:5672');

module.exports = broker;

broker.init

Use broker.init to initialize broker, creating connections and channels based on broker options. Example:

// main.js
const broker = require('./broker');

(async() => {
  await broker.init();
})();

broker.assertExchanges

Use broker.assertExchanges to create or check exchanges. It expects to receive an array of exchanges (exchange options). Example:

const broker = require('./broker');

const exchanges = [
  { name: 'user_events', type: 'direct' },
  { name: 'repo_events', type: 'topic', options: { durable: true } },
  { name: 'commit_events', type: 'fanout' },
];

(async() => {
  await broker.assertExchanges(exchanges);
})();

broker.consume

broker.consume expects to receive an object with queue and array of bindings and callback. Example:

const broker = require('./broker');

const queue = {
  name: 'queue.name',
  options: {
    durable: true,
  },
};

const bindings = [
  { exchange: 'user_events', routingKey: 'user_events.routingKey' },
  { exchange: 'repo_events', routingKey: 'repo_events.routingKey' },
];

(async() => {
  await broker.consume({ queue, bindings }, (message, /* fields */) => {
    // do something
    // throw an error to reject message
  });
})();

broker.publish

broker.publish expects to receive exchange, routing key, message and publish options. Example:

const options = { persistent: true };

broker.publish({
    exchange: 'user_events',
    routingKey: 'user_events.routingKey',
    message: { message: 'message' },
    options,
  })

broker.channels

Use broker.channels to get channels. Examples:

const broker = require('./broker');
let context;
let channel;

//consumer
context = 'consumer';
channel = broker.channels[context].default;

//publisher
context = 'publisher';
channel = broker.channels[context].default; // or broker.channels[context].confirmation;

Broker options

Option	Description	Required	Default
channelMax	number max of channels (max 3)	no	3
publisher	publisher object	no	_
publisher.default	create publish channel without confirmation	no	true
publisher.confirmation	create publish channel with confirmation	no	false
consumer	consumer object	no	_
consumer.default	create consume channel	no	true
prefetch	channel prefetch count	no	1

Exchange options

Option	Description	Default
type	direct, topic, fanout	empty string (deafault)
name	exchange name	null
options	options used in assertExchange	null

Queue options

Option	Description	Default
name	queue name	null
options	options used in assertQueue	null

Binding options

Option	Description	Default
exchange	exchange name	null
routingKey	routing key name	null