server.js

require('dotenv').load();

[
'CURRENT_KEY',
'AUTH0_CALLBACK',
'SIGNATURE_KEY_' + process.env.CURRENT_KEY,
'ENCRYPTION_KEY_' + process.env.CURRENT_KEY,
'AUTH0_DOMAIN',
'AUTH0_CLIENT_ID',
'AUTH0_CLIENT_SECRET',
'COOKIE_SECRET'
].forEach(function (v) { 
    require('assert').ok(process.env[v] !== undefined, v + ' environment variable not set.'); 
});

var logger = require('./logger')
    , app = require('./app');

app.set('port', process.env.PORT || 3000);

logger.info({ port: app.get('port') }, 'setting up HTTP listener');
var server = app.listen(app.get('port'), function (error) {
    if (error) throw error;
    logger.info({ port: app.get('port'), current_key: process.env.CURRENT_KEY }, 'listening');
});