RabbitMQ Client Events

Notes

• This implementation is for using rabbitmq with events following event-driven architecture. The library is mainly configured for topic exchanges, but could be changed (this is the most optimal ways for EDA).
• rabbitmq topic exchange example:

Route Key

• For creating routes keys is used https://github.com/fmvilas/topic-definition, formatted as follows:

Installation

npm i rabbitmq-events-client

Implementation

Publisher

import RabbitmqClientEvents from "rabbitmq-events-client";

const rabbitmqClientPublisher = new RabbitmqClientEvents("amqp://rabbitmq:rabbitmq@localhost", 'service name', 'exchange name', 'company name');

rabbitmqClientPublisher.connectToServer()
  .then(() => {
    setInterval(async () => {
      await rabbitmqClientPublisher.publish(event, {
        data: 123,
        meta: {},
      }
    }, interval);
  })
  .catch((e) => {
    console.error(e);
  });

publish function will create route key as mentioned above

Consumer / Worker

import RabbitmqClientEvents from "rabbitmq-events-client";

const rabbitmqClientConsumer = new RabbitmqClientEvents("amqp://rabbitmq:rabbitmq@localhost", 'service name', 'exchange name', 'company name');

rabbitmqClientConsumer
  .connectToServer()
  .then(async () => {
    await rabbitmqClientConsumer.subscribe('queue name', 'key', (msg) => {
      const content = JSON.parse(msg.content.toString());
      //do things!!
      //then acknowledge message
      rabbitmqClientConsumer.ackMessage(msg);
      //or reject message
      rabbitmqClientConsumer.nackMessage(msg);
    });
  })
  .catch((e) => {
    console.error(e);
  });

Modify Route Key

its posible alter the route key before publish a message, example:

...
rabbitmqClientEvents.setPublishKey({
        company: 'company',
        service: 'service',
        version: 1,
        entity: 'entity',
      });
await rabbitmqClientPublisher.publish...

Dead Letter Exchange

By default will create a dead letter exchange and a queue, it's possible to turn off this option in the subscribe function:

rabbitmqClientConsumer.subscribe('queue name', 'key', (msg) => {
      const content = JSON.parse(msg.content.toString());
      //do things!!
      rabbitmqClientConsumer.ackMessage(msg);
    },{
      createDeadLetterQueue: false
});