A Node.js script for LineRate extolling the moveRequest() method

vsm-move-request.js

// Move request example
"use strict";

var vsm = require('lrs/virtualServerModule');
var redis = require('redis');
var url = require('url');
var async = require('async');
var trialUsersServer = undefined;
var client = redis.createClient();
var userAccountDB = 1;

// Select the dedicated db for user accounts
client.select(userAccountDB, function(err, result){
  if(err){
    return err;
  }
});

client.on('error', function(err){
  console.log('Error ' + err);
});

// Connect to the redis server and populate with sample entries
client.on('connect', function(){
  console.log("Connected to redis server");
  client.mset("John", "trial", "Jane", "paid", "Donald", "trial");
});

function getUsername(servReq, callback){
  var url_parts = url.parse(servReq.url, true);
  var query = url_parts.query;
  console.log(query.name);
  return callback(null, query.name);
}

// Determine whether the user is a trial or paid user of the services
function getUserStatus(username, callback){
  if (!username){
    console.log("No username found");
    return callback(null, false);
  }

  // If the query string contains a name, process request
  // based on user's trial or paid 'status'
  client.get(username, function(err, result){
    if (err){
      throw err;
    }

    if (!result){
      console.log("User " + username + " not found");
      client.set(username, "trial", function(err, result){
        if(err){
          return callback(err);
        }

        if (result){
          console.log("User " + username + " added");
          return callback(null, true);
        }
      });
    }
    else{
      console.log("User " + username + " found");
      if (result === "trial"){
        return callback(null, true);
      }
      else if(result === "paid"){
        return callback(null, false);
      }
      else{
        console.log("Parse error from redis value");
        return callback(null, false);
      }
    }
  });
}

function processRequest(isTrialUser, servReq, servResp, cliReq){
  if (trialUsersServer && isTrialUser){
    trialUsersServer.moveRequest(servReq, servResp);
  }
  else{
    cliReq();
  }
}

var onUserRequest = function(servReq, servResp, cliReq){
  async.waterfall([
      function(callback){
        getUsername(servReq, callback);
      },
      function(username, callback){
        getUserStatus(username, callback);
      },
      function(isTrialUser, callback){
        processRequest(isTrialUser, servReq, servResp, cliReq);
      }
    ], function(err, result){
      if(err){
        console.log("Error processing request " + err);
        processRequest(false, servReq, servResp, cliReq);
      }
    });
}

var onPaidUsersServerExists = function(vs){
  console.log("Paid users' server ready");
  vs.on('request', onUserRequest);
}

vsm.on('exist', 'paidUsersServer', onPaidUsersServerExists);

var onTrialUsersServerExists = function(vs){
  console.log("Trial users' server ready");

  trialUsersServer = vs;
}

vsm.on('exist', 'trialUsersServer', onTrialUsersServerExists);