Node.js Express config file pattern

config.js

const config = require('../config.json');
module.exports = config;

gistfile1.txt

{
    "port": 8020,
    "self": "http://localhost:8020",
    "session": {
        "key": "xxx"
    },
    "db": {
        "host": "127.0.0.1",
        "database": "xxx",
        "user": "xxx",
        "password": "xxx"
    },
    "timezone": "Europe/Tallinn",
    "mail": {
        "from": "noreply@xxx",
        "smtp": {
            "port": 25,
            "host": "xxx"
        }
    }
}

mail.js

const util = require('util');
const nodemailer = require('nodemailer');
const config = require('../config');
const transport = nodemailer.createTransport(config.mail.smtp);

// Sends mail. Wrapped into a promise.

const sendMail = util.promisify((options, cb) =>
    transport.sendMail(options, cb));

exports.send = sendMail;