server.js

#!/bin/env node
//  OpenShift Geospatial Node application
var express = require('express');
var fs      = require('fs');
var mongodb = require('mongodb');

/**
 *  Define a nodejs application ... a namespace function.
 */
var NodeApp = function() {

	//  Scope.
	var self = this;
	
    /**
     *  Set up server IP address and port # using env variables/defaults.
     */
    self.setupVariables = function() {

		// Pickup Mongo environment variables
		
		self.dbServer = new mongodb.Server(process.env.OPENSHIFT_MONGODB_DB_HOST,
			parseInt(process.env.OPENSHIFT_MONGODB_DB_PORT, 10));

		self.db = new mongodb.Db(process.env.OPENSHIFT_APP_NAME, self.dbServer, {auto_reconnect: true, safe: false});

		self.dbUser = process.env.OPENSHIFT_MONGODB_DB_USERNAME;
		self.dbPass = process.env.OPENSHIFT_MONGODB_DB_PASSWORD;
		
		// Inject db reference into routes module
		
		require('routes').setDb(self.db);		
		
		//  Web app environment variables

		self.ipaddress = process.env.OPENSHIFT_INTERNAL_IP;
		self.port      = process.env.OPENSHIFT_INTERNAL_PORT || 8080;

		if (typeof self.ipaddress === "undefined") {
		
			//  Log errors on OpenShift but continue w/ 127.0.0.1 - this
			//  enables running the app locally.

			console.warn('No OPENSHIFT_INTERNAL_IP var, using 127.0.0.1');
			self.ipaddress = "127.0.0.1";
		}

	}; /* setupVariables */

	/**
	 *  terminator === the termination handler
	 *  Terminate server on receipt of the specified signal.
	 *  @param {string} sig  Signal to terminate on.
	 */
	self.terminator = function(sig){
		if (typeof sig === "string") {
			console.log('%s: Received %s - terminating sample app ...',
				Date(Date.now()), sig);
			process.exit(1);
		}
		console.log('%s: Node server stopped.', Date(Date.now()) );
	}; /* terminator */

    /**
     *  Set termination handlers (for exit and a list of signals).
     */
    self.setupTerminationHandlers = function(){
        //  Process on exit and signals.
        process.on('exit', function() { self.terminator(); });

        ['SIGHUP', 'SIGINT', 'SIGQUIT', 'SIGILL', 'SIGTRAP', 'SIGABRT',
         'SIGBUS', 'SIGFPE', 'SIGUSR1', 'SIGSEGV', 'SIGUSR2', 'SIGTERM'
        ].forEach(function(element, index, array) {
            process.on(element, function() { self.terminator(element); });
        });
    }; /* termination handlers */


    /*  ================================================================  */
    /*  App server functions (main app logic).                            */
    /*  ================================================================  */

    /**
     *  Initialize the server (express): create the routes using
     *  module routes.js, and then register the handlers.
     */
    self.initializeServer = function() {
        var routes = require('routes').createRoutes(self);
        self.app = express();

        //  Register handlers for the app (from the routes collection).
        for (var r in routes) {
            self.app.get(r, routes[r]);
        }
    }; /* initialize server */


	/**
	 *  Initialize application: housekeeping, 
	 * cache static content, termination handler.
	 */
	self.initialize = function() {
		self.setupVariables();
		require('routes').populateCache(fs);
		self.setupTerminationHandlers();

		// Create the express server and routes.
		self.initializeServer();
    }; /* initialize app */


	/**
	 *  Start the server and the application.
	 */
	self.start = function() {

		//  Start the app on the specific interface (and port).
		console.log('%s self.start entered', Date(Date.now()) );

		self.app.listen(self.port, self.ipaddress, function() {
			console.log('%s: Node server started on %s:%d ...',
				Date(Date.now() ), self.ipaddress, self.port);
		});
	}; /* app start */

	/**
	 *  Connect db and then callback to start the application.
	 */
	self.connectDb = function( appStart ) {
		self.db.open(function(err, db) {
			if ( err ) { throw err; }
			self.db.authenticate(self.dbUser, self.dbPass,  function(err, result) {
				if (err) { throw err; }
			});
			appStart();
		});
	}; /* Connect db */

};   /* Application.  */

/*  ================================================================  */
/*  Main                                                              */
/*  ================================================================  */
var theApp = new NodeApp();
theApp.initialize();
theApp.connectDb( theApp.start );