lib/server.js
function start(app) {
    /**
     * Create HTTP server.
     */

    const config = require('./config')();
    port = normalizePort(config.get('port'));
    server = http.createServer(app);

    /**
     * Listen on provided port, on all network interfaces.
     */

    app.set('port', port);
    server.listen(port);
    server.on('error', onError);
    server.on('listening', onListening);

    return server;
}
function start(app) {
    /**
     * Create HTTP server.
     */

    const config = require('./config')();
    port = normalizePort(config.get('port'));
    server = http.createServer(app);

    /**
     * Listen on provided port, on all network interfaces.
     */

    app.set('port', port);
    server.listen(port);
    server.on('error', onError);
    server.on('listening', onListening);

    return server;
}
function start ( app ) { /**
     * Create HTTP server.
     */ const config = require ( './config' ) ( ) ; port = normalizePort ( config . get ( 'port' ) ) ; server = http . createServer ( app ) ; /**
     * Listen on provided port, on all network interfaces.
     */ app . set ( 'port' , port ) ; server . listen ( port ) ; server . on ( 'error' , onError ) ; server . on ( 'listening' , onListening ) ; return server ; }
Get port from nconf
Get port from nconf