AMQPPoster

A library for building communication between microservices. It has simple and small API. It works with amqplib and oriented to RabbitMQ.

Installation

npm install amqp-poster

API

Instance

const Poster = require('amqp-poster');

(async () => {
	const poster = new Poster(options);
	
	await poster.init();
})();

options

{
	name: 'TestService',
	uid:  'inst1',
	subscribe: [{
		exchange:       '',
		oncePerService: true
	}],
	prefetch: 10,
	server: {
		port:     5672,
		hostname: 'localhost',
		username: 'guest',
		password: 'guest'
	}
}

| key | required | type | description | |-----|----------|------|-------------| | name | true | string | Service name. Also it is queue name for listening | | uid | | string | String to identify owned queues | | subscribe | | array | Collection of exchanges to subscribe | | subscribe[].exchange | true | string | Name of exchange to subscribe | | subscribe[].oncePerService | | boolean | Apply round robin to messages for one service by name (default false) | | prefetch | | integer | How many messages process at one time (default 1) | | server | true | string | Connection url like 'amqp://guest:guest@localhost:5672' | | server | true | object | Object of connection config. May have next keys: protocol, hotname, port, username, password, locale, frameMax, heartbeat, vhost|

Send messages

try {
	let resp = await poster.send('ServiceName', reqObj)
	// some logic
} catch (err) {
	// Handle error
}

reqObj - object or other variable to send

respObj - response object

err - error from respond-side

Message Handler for incoming messages

poster.setMessageHandler(async (reqObj) => {
	// some logic
	
	// throw new Error('Some error');
	// or
	
	return respObj;
});

reqObj - object or other variable was sent

respObj - object or other variable to send as answer. Can be Promised value

Publish broadcast message

await poster.publish('ExchangeName', reqObj);

Handle broadcast messages

poster.setBroadcastHandler(function (reqObj) {
	// some logic
});