jd-amqp-mgr

0.1.18 • Public • Published

AMQP Connection Manager

Wrapper of Amqplib
It won't create any queue nor exchange, all are supposed to already exist.
Handle reconnections and connection/channel/queues associations

Usage :

var AMQP = require('jd-amqp-mgr');
var AmqpMgr = new AMQP("amqp://app:app@localhost:5672", opts);
// opts can contain socket_opts to be used for tls mutual auth with RMQ server
// opts.reconnect_delay : specify delay between reconnect attempts.

AmqpMgr.on('ready', function(){
  let channel = await AmqpMgr.getChannel(['queue1', 'queue2'], function(msg){
    console.log(msg);
  });

  channel.publish('my.exchange','my.routing.key',{test:1,is:'ok'},{hdr1:"somevalue"},{expiration:2000})
});

alternative

var AMQP = require('jd-amqp-mgr');

var AmqpMgr = new AMQP("amqp://app:app@localhost:5672");
AmqpMgr.getChannel('queue1', function(msg){ console.log(msg); })
.then(ch => { ch.publish('my.exchange','my.routing.key',{test:1,is:'ok'},{hdr1:"somevalue"},{expiration:2000}) })
.catch(e => {});

Only to be used for 100% json payloads.
AMQP 0.9.1

AmqpMgr :

  • Manages automatic reconnections to server, and reconnect channels

  • Emits a ready event upon first connection to RabbitMQ is established, and reconnected/disconnected afterwards

  • checkQueues(in_queues) : check existence of queues prior to create a channel (cause one invalid queue causes channel to be closed) in_queues : array of string

  • getChannel(in_queues, callback_fn) : Create a channel that will consume message from queues in in_queues

    • returns a Promise that resolves with an instance of AMQPTSPChannel
    • in_queues : Queues that this channel will consume
      • array of strings
      • simple string
      • empty (if intended for publication only)
    • callback_fn : function invoked upon message reception.
    • Request to getChannel will be queued until the first AMQP connection gets up. After first connection to AMQP, getChannel will fail if there is no ongoing connections.
  • removeChannel(in_channel_id) : Remove a channel. Disconnection from this channel must be done directly over that channel.

  • publish(exchange, routing_key, payload, headers,properties) : Publishes a message on an amqp channel dedicated to publishing.

    • payload is mandatory, object or array
    • headers and properties are optional. note that the property content_type will necessarily be set to application/json

AMQPTSPChannel

  • Represents a channel between the app and the RMQ server. Consumes on queues, and is able to publish message to exchanges. Automatic reconnection is covered.
  • publish(exchange, routing_key, payload, headers, properties) : Publish a message over this channel
    • Returns a Promise
    • payload,headers,properties must be object
    • Property content_type is automatically set to application/json
    • Throw error if invalid attributes.
    • Failure to send the message (invalid exchange as an example) will not end up with an error being triggered related to the publish call, but the amqp server will close the Channel. The close event on a channel triggers the reconnection.
  • addQueues(in_queues) : Start consuming messages from that queue
  • removeQueue(in_queue) : stop consuming a queue.
  • pause(in_queue) : pause consuming a queue.
  • resume(in_queue) : resume consuming a queue.
  • close() : Ends this channel

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npm i jd-amqp-mgr

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Version

0.1.18

License

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Collaborators

  • jdarrort