data-layer-rabbitmq: A JavaScript repository from BDSwiss

#Data Layer for RabbitMQ Data layer for microservices communication using RabbitMQ

npm i data-layer-rabbitmq

##Configuration Object This object defines the RabbitMQ architecture that will be created (if it doesn't exists already). Below the different options are described.

###Set connection credentials In order to define connection credentials you need add as key the CONNECTION string and as value an object with the following structure:

{
  url: 'my-rabbitmq-url-with-credentials'
}

If the CONNECTION key isn't defined then the default localhost credential are used.

###Exchange to Queue Bindings In order to define one or more Exchange - Queue bindings you need to add as key the BIND_QUEUE string and as value an array with objects with the following structure:

{
  EXCHANGE: { //An object representing the exchange
    ID: 'my-exchange', //A String representing the id of the exchange
    TYPE: 'direct', //A String representing the type of the exchange
    OPTIONS: { //An object representing the RabbitMQ options for the exchange
      durable: true,
      autoDelete: false
    }
  },
  QUEUE: { //An object representing the queue (if it is undefined then a non-durable queue is added
    ID: 'my-queue', //A String representing the id of the queue
    OPTIONS: {  //An object representing the RabbitMQ options for the queue
      durable: true,
      autoDelete: false
    }
  },
  KEYS: [ //An array with the routing keys (if it is undefined then the '' routing key will be added
    'some-route',
    'another-route'
  ]
}

###Exchange to Exchange Bindings In order to define one or more Exchange - Exchange bindings you need to add as key the BIND_EXCHANGE string and as value an array with objects with the following structure:

{
  SOURCE: { //An object representing the source exchange
    ID: 'my-source-exchange', //A String representing the id of the exchange
    TYPE: 'topic', //A String representing the type of the exchange
    OPTIONS: { //An object representing the RabbitMQ options for the exchange
      durable: true,
      autoDelete: false
    }
  },
  DESTINATION: { //An object representing the destination exchange
    ID: 'my-destination-exchange', //A String representing the id of the exchange
    TYPE: 'fanout', //A String representing the type of the exchange
    OPTIONS: { //An object representing the RabbitMQ options for the exchange
      durable: true,
      autoDelete: false
    }
  },
  KEYS: [ //An array with the routing keys (if it is undefined then the '' routing key will be added
    'some-route',
    'another-route'
  ]
}

###Consume Queues In order to consume one or more queues you need to add as key the CONSUME_QUEUE string and as value an array with objects with the following structure:

{
  QUEUE: { //An object representing the queue
    ID: 'my-queue', //A String representing the id of the queue
    OPTIONS: {  //An object representing the RabbitMQ options for the queue
      durable: true,
      autoDelete: false
    }
  }
}

##Instantiate In order to instantiate DataLayerRabbitMQ import the class and pass to the constructor the configuration object.

var config = {
  CONNECTION: {
    url: 'my-rabbitmq-url-with-credentials'
  },
  BIND_QUEUE: [
    {
      EXCHANGE: {
        ID: 'my-exchange',
        TYPE: 'direct',
        OPTIONS: {
          durable: true,
          autoDelete: false
        }
      },
      QUEUE: {
        ID: 'my-queue',
        OPTIONS: {
          durable: true,
          autoDelete: false
        }
      },
      KEYS: [
        'some-route',
        'another-route'
      ]
    }
  ],
  CONSUME_QUEUE: [
    {
      ID: 'my-queue',
      OPTIONS: {
        durable: true,
        autoDelete: false
      }
    }
  ]
};

var DataLayerRabbitMQ = require('data-layer-rabbitmq');
var rmq = new DataLayerRabbitMQ(config);

##API ###publish(exchange:object, routingKey:string, message:*, [options:object]):Promise Sends a message to an exchange.

rmq.publish(
  {
    ID: 'my-exchange',
    TYPE: 'direct',
    OPTIONS: {
      durable: true,
      autoDelete: false
    }
  },
  'some-route',
  'message-goes-here',
  {
    persistent: true
  }
).catch(
  function(err){
    throw new Error(err);
  }
);

##Events The DataLayerRabbitMQ instances emit events.

rmq.on(DataLayerRabbitMQ.EVENTS.CONNECTED, function(){
  //do something
})

###DataLayerRabbitMQ.EVENTS.CONNECTED This event is emitted when the connection is established ###DataLayerRabbitMQ.EVENTS.DISCONNECTED This event is emitted on disconnections ###DataLayerRabbitMQ.EVENTS.MESSAGE_ARRIVED This event is emited when a message arrives.

rmq.on(DataLayerRabbitMQ.EVENTS.MESSAGE_ARRIVED, function(queue, message){
  //ack the message
  queue.ack(message);
  //or reject the message
  queue.reject(message);
});

###DataLayerRabbitMQ.EVENTS.MESSAGE_DELIVERED This event is emitted when a message arrives at the RabbitMQ

rmq.on(DataLayerRabbitMQ.EVENTS.MESSAGE_DELIVERED, function(message){
  //do something
});

###DataLayerRabbitMQ.EVENTS.MESSAGE_DELIVERY_ERROR This event is emitted when a message fails to arrive at the RabbitMQ

rmq.on(DataLayerRabbitMQ.EVENTS.MESSAGE_DELIVERY_ERROR, function(message){
  //do something
});

##Gulp commands ###Dev watcher It runs the jshint on the codebase

gulp

###RabbitMQ status Get info for the local RabbitMQ node.

gulp rmq-info

###RabbitMQ reset (USE WITH CAUTION!!!) Delete all data from the local RabbitMQ node.

gulp rmq-delete-all

Contributing

Data Layer for RabbitMQ follows the GitFlow branching model. The master branch always reflects a production-ready state while the latest development is taking place in the develop branch.

Each time you want to work on a fix or a new feature, create a new branch based on the develop branch: git checkout -b BRANCH_NAME develop. Only pull requests to the develop branch will be merged.

Versioning

Data Layer for RabbitMQ is maintained by using the Semantic Versioning Specification (SemVer).

bdswiss/data-layer-rabbitmq

Contributing

Versioning