rabbit-worker

rabbit-worker

Very basic node module for creating and consuming from RabbitMQ work queues

Why?

Because I am writing a lot of small services that use this sort of queue. It is just a light rabbit.js wrapper (if for some weird reason you were hoping to use this project, I would instead you use that library directly) that defaults to persistant queues and automatically reconnects on connection failures.

Synopsis

var rabbitWorker = require('rabbit-worker');
var worker = new rabbitWorker.Worker('localhost', 'work_queue_1', function (message, ack) {
    console.log('got message', message);
    ack();					//important! Signals to the queue that the work has been completed
});
	
var tasker = new rabbitWorker.Tasker('localhost', 'work_queue_1');
if (tasker.isReady()) {
    tasker.publish('New message');
} else {
    tasker.once('ready', tasker.publish.bind(tasker, 'New message');
} 

TODO

• Support for publisher confirms would be rad (I am currently living dangerously and not using them in the interest of code simplicity). Would require either a modification in the upstream rabbit.js library or that this module be converted to use amqplib as its upstream library directly (amqplib being the core module that rabbit.js relies on).

jsdoc-to-markdown output

rabbit-worker

Light wrapper over the rabbit module to easily create persistent workers and taskers.

Version: 0.0.1
Author: notnarb

• rabbit-worker
  • ~Worker(rabbitserver, routingKey, workerFunction)
  • ~Tasker(rabbitserver, routingKey) ⇐ event.EventEmitter
    • .publish(message)
    • .isReady() ⇒ Boolean

rabbit-worker~Worker(rabbitserver, routingKey, workerFunction)

connects to the specified rabbitmq server as a worker for the specified routing key

Kind: inner method of rabbit-worker

Param	Type	Description
rabbitserver	String	The hostname of the rabbit server to use
routingKey	String	the routing key to listen on
workerFunction	function	the function to call for each message. This function is called with 2 arguments: 'message', and 'ack'. Message is a string representation of the data passed and 'ack' is a function that must be called to acknowledge the function. Note: for simplicity: the function 'requeue' and 'discard' are omitted though they wouldn't be hard to add

Example

var worker = new Worker('localhost', 'work_queue_1', function (message, ack) {
    console.log('got message', message);
    ack();					//important! Signals to the queue that the work has been completed
})

rabbit-worker~Tasker(rabbitserver, routingKey) ⇐ event.EventEmitter

connects to the specified rabbitmq server as a publisher for the specified routing key. Emits a 'ready' event when it can start taking publish commands.

Kind: inner method of rabbit-worker
Extends: event.EventEmitter

Param	Type	Description
rabbitserver	String	The hostname of the rabbit server to use
routingKey	String	the routing key to listen on

Example

var tasker = new Tasker('localhost', 'work_queue_1');
if (tasker.isReady()) {
    tasker.publish('New message');
} else {
    tasker.once('ready', tasker.publish.bind(tasker, 'New message');
} 

• ~Tasker(rabbitserver, routingKey) ⇐ event.EventEmitter
  • .publish(message)
  • .isReady() ⇒ Boolean

tasker.publish(message)

Publishes a message to the queue

Kind: instance method of Tasker
Throws:

• Error - if the queue is currently unavailable, this throws an error

Param	Type	Description
message	String	message to publish to the queue

tasker.isReady() ⇒ Boolean

Checks to see if the tasker is currently connected to the queue

Kind: instance method of Tasker
Returns: Boolean - - true if currently can accept publish arguments