off-sqs-debearloper/lib/receiver.js

Helper app that manages SQS and RabbitMQ transactions

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

var getSQSMessages = function(){
  var receiveParams = {
    QueueUrl: this.queueUrl,
    MaxNumberOfMessages: this.MaxNumberOfMessages,
    WaitTimeSeconds: this.WaitTimeSeconds //Change to 20 seconds?
  };

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

  sqs.receiveMessage(receiveParams, function(err, data){
    if(err){
      console.log("/38, " + err);
    }else{
      if(data['Messages']){
        // Start the crawling service
        var parsedData = 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){
          if (err) {
            console.log("/54, " + err);
          };
        });
      };
      getMessages.call(self);
    };
  });
};

var getRabbitMQMessages = function(){
  var url   = this.queueUrl,
      self  = this;

  amqp.connect('amqp://localhost').then(function(conn){
    process.once('SIGINT', function(){
      conn.close();
    });
    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(data);
        }, {noAck: true});
      });

      return ok.then(function(_consumeOk){
      });
    });
  }).then(null, console.warn);
};

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

  if(config.env.production || config.env.qa){
    return this.getSQSMessages();
  }else{
    return this.getRabbitMQMessages();
  }
};