gistfile1.js

var url        = require('url'),
    parsedUrl  = url.parse(process.env.DB || 'mongodb://localhost/mdocs');

var dbSettings = {
  host:     parsedUrl.hostname,
  port:     parseInt(parsedUrl.port || 27017, 10),
  name:     parsedUrl.pathname.substr(1),
  user:     parsedUrl.auth ? parsedUrl.auth.split(':')[0] : null,
  password: parsedUrl.auth ? parsedUrl.auth.split(':')[1] : null
};

module.exports = function gtDb(callback) {

  var mongoserver = new mongodb.Server(dbSettings.host, dbSettings.port, {
        auto_reconnect: true,
        socketOptions: { keepAlive: 300 },
        poolSize: 10
      });
  
  var dbConnector = new mongodb.Db(dbSettings.name, mongoserver, {safe: true});

  dbConnector.open(function(err, db){
    if ( err ) {
      console.log('error connecting to the db, exiting');
      return callback(err);
    }

    if(dbSettings.user && dbSettings.password){
      console.log("authenticating to mongodb");
      db.authenticate(dbSettings.user, dbSettings.password, function(err){
        if(err){
          console.log('database authentication fail');
          return callback(err);
        }
        return callback(null, db);
      });
    }else{
      return callback(null, db);
    }
  });

}