Better logs on Node.js Express.js +Passport.js +Heroku

gistfile1.js

    
    // create a new token to track logged in users
    express.logger.token('user', function(req, res){ 
      // req.user is the deault passport.js variable, log the user id
      return req.user ? req.user._id : '-'; 
  
    });
    
    // use this function on Heroku to get the remote IP
    express.logger.token('ip', function(req, res){
      return req.headers["x-forwarded-for"] ? req.headers["x-forwarded-for"].split(',').pop() : req.connection.remoteAddress;
    });
    
    
    app.use(express.logger(':ip :user ":method :url" :status :res[Content-Length] :response-time ":referrer"'));