Microservice Utils

Contains rabbitmq-based transport for establishing a net of loosely coupled microservices with a simple rpc-style calling interface.

Install

npm i ms-amqp-transport -S

Heavily relies on dropbox/amqp-coffee lib for establishing communication to rabbitmq.

Notice, Upgrade from 3.x to 4.x

• ms-validation became a peer dependency, >= 3.x.x
• node must be of version >= 6.2.0
• npm must be >= 3.x.x

Rest is exactly the same as before

Usage

const AMQPTransport = require('ms-amqp-transport');

const amqp = new AMQPTransport(config);

amqp.connect().then((amqpInstance) => {
  // amqp === amqpInstance
  // we are connected, do things here
});

In a more generic case, you want to use .connect(config, messageHandler) helper, which would create queues and bind them to exchanges for you based on the provided configuration. Consider the following example:

const AMQPTransport = require('ms-amqp-transport');

// message routers
function router(message, headers, actions, next) {
  switch (headers.routingKey) {
    case 'very.important.route':
      // examine message, do smth with it, reply with next callback
      return next(null, 'delivered!');
  }
}

AMQPTransport.connect(configuration, router).then(function (amqp) {
  // amqp instance
  // you can use it do directly send messages
  // amqp.publish
  // amqp.publishAndWait
  // amqp.send
  // amqp.sendAndWait
  //
  // This all internally uses [amqp-coffee publish method](https://github.com/dropbox/amqp-coffee#connectionpublishexchange-routingkey-data-publishoptions-callback)
  // If message fails - it will be rejected in a promise
});

amqp.publish(route, message, [options])

Publishes message to a route on an exchange defined in configuration

• route - routikngKey, must be string
• message - anything that can be stringified, it's advised for it to be small
• options:
  • options.timeout - sets TTL on the message

amqp.publishAndWait(route, message, [options])

Same as previous one, but specifies a correlation id and replyTo header, therefore allowing one to receive a response.

• route - routikngKey, must be string
• message - anything that can be stringified, it's advised for it to be small
• options:
  • options.timeout - sets TTL on the message

amqp.send(queue, message, [options])

Sends message directly to a queue

• queue - queue name, must be string
• message - anything that can be stringified, it's advised for it to be small
• options:
  • options.timeout - sets TTL on the message

amqp.sendAndWait(queue, message, [options])

Sends message directly to a queue and sets replyTo and correlationId headers

• queue - queue name, must be string
• message - anything that can be stringified, it's advised for it to be small
• options:
  • options.timeout - sets TTL on the message

Tests

Run make test in order to run tests in the dockerized infrastructure. Currently runs tests in 5.x.x, 4.x.x and 0.10.40. Add more targets if you wish to.