app.js

var bodyParser = require('body-parser')
  , cluster = require('cluster')
  , express = require('express')
  , expressJson = require('express-json')
  , expressWinston = require('express-winston')
  , swagger_node = require('swagger-node-express')
  , swaggerResources = require('./swaggerResources.js')
  , url = require('url')
  , winston = require('winston')
  , _ = require('lodash');

if (cluster.isMaster) {
    var nCpus = require('os').cpus().length;
    console.log('Initializing app');
    for (var i=0; i<_.min([4, nCpus]); i++) {
        cluster.fork();
    }
    
    cluster.on('exit', function(worker) {
        console.log('Worker %d died; replacing', worker.id);
        cluster.fork();
    });
} else {
    startApp();    
}

function startApp() {
    var app = express();
    app.use(expressJson());
    //app.use(bodyParser.urlencoded());
    app.use('/swagger', express.static(__dirname + '/public/swagger'));
    app.use(expressWinston.logger({
        transports: [
            new winston.transports.Console({
                colorize: true
            })
            //transports can be custom functions, built in, or user supported: 
            //file, http, mongoDB, couchDB, mysql, loggly, redis, mail
        ]
    }));

    var swagger = swagger_node.createNew(app);
    swaggerResources.addRoutes(swagger);
    startServer(app, swagger);
}

function startServer(app, swagger) {
    swagger.configureSwaggerPaths("", "/docs", "");
    swagger.configure('http://localhost:3000/','0.1');
    var server = app.listen(3000, function () {
        var host = server.address().address;
        var port = server.address().port;
        console.log('Worker %d listening at http://%s:%s', 
            cluster.worker.id, host, port);
    });
}