nibi/lib/receiver.js

Extremely easy management of queues with RabbitMQ and/or AmazonSQS

var AWS = require('aws-sdk')
var amqp = require('amqplib')
var when = require('when')
var utils = require('./utils')
var config = require('./config')

var getSQSMessages = function () {
  var receiveParams = {
    QueueUrl: this.queueUrl,
    MaxNumberOfMessages: this.MaxNumberOfMessages,
    WaitTimeSeconds: this.WaitTimeSeconds
  }

  AWS.config.update(config.awsConfigFile)
  var sqs = new AWS.SQS()
  var self = this

  sqs.receiveMessage(receiveParams, function (err, data) {
    if (data['Messages']) {
      // Start the crawling service
      var parsedData = self.parseMessage(data)
      self.callback(parsedData)

      // deletes the received messages from the queue
      var toDelete=[]

      for (var i=0; i<data['Messages'].length; i++){
        toDelete.push({
          'Id':data['Messages'][i]['MessageId'],
          'ReceiptHandle':data['Messages'][i]['ReceiptHandle']
        })
      }

      var deleteParams = {
        QueueUrl: self.queueUrl,
        Entries : toDelete
      }

      sqs.deleteMessageBatch(deleteParams, function (err, deleted) {})
    }

    getMessages.call(self)
  })
}

var getRabbitMQMessages = function () {
  var url = this.queueUrl
  var route = utils.buildRoute(this.config)
  var self = this

  amqp.connect(route).then(function (conn) {
    return conn.createChannel().then(function (channel) {
      var ok = channel.assertQueue(url, {durable: false})

      ok = ok.then(function (_qok) {
        return channel.consume(url, function (msg) {
          var data = []

          data.push(msg.content.toString())

          self.callback(null, data)
        }, {noAck: true})
      })

      return ok.then(function (_consumeOk) {})
    })
  }).then(null, function (err) {
    self.callback(err)
  })
}

module.exports = getMessages = function () {
  this.getSQSMessages = getSQSMessages
  this.getRabbitMQMessages = getRabbitMQMessages

  return (config.service === 'rabbit')
    ? this.getRabbitMQMessages()
    : this.getSQSMessages()
}