server.js

var http = require('http'),
    url = require('url'),
    path = require('path'),
    fs = require('fs');
var mimeTypes = {
    "html": "text/html",
    "jpeg": "image/jpeg",
    "jpg": "image/jpeg",
    "png": "image/png",
    "js": "text/javascript",
    "css": "text/css"
};
port = process.env.PORT;

var server = http.createServer(function (req, res) {
    var uri = url.parse(req.url).pathname;
    var filename = path.join(process.cwd() + '/web/', unescape(uri));
    var stats;

    try {
        stats = fs.lstatSync(filename); // throws if path doesn't exist
    } catch (e) {
        res.writeHead(404, {
            'Content-Type': 'text/plain'
        });
        res.write('404 Not Found\n');
        res.end();
        return;
    }


    if (stats.isFile()) {
        // path exists, is a file
        var mimeType = mimeTypes[path.extname(filename).split(".").reverse()[0]];
        res.writeHead(200, {
            'Content-Type': mimeType
        });

        var fileStream = fs.createReadStream(filename);
        fileStream.pipe(res);
    } else if (stats.isDirectory()) {
        var fileStream = fs.createReadStream(filename + '/index.html');
        fileStream.pipe(res);
    } else {
        // Symbolic link, other?
        // TODO: follow symlinks?  security?
        res.writeHead(500, {
            'Content-Type': 'text/plain'
        });
        res.write('500 Internal server error\n');
        res.end();
    }

}).listen(port);
console.log('Server listening at http://localhost:' + server.address().port);