My usual nconf wrapper

index.js

"use strict";

/**
Save as config/index.js

Config files =
- config/config.json
- config/config.$NODE_ENV.json
- config/config.$NODE_ENV.$USER.json
**/

var path = require('path');
var fs = require('fs');

var conf = module.exports = require('nconf')
.argv()
.env()
.defaults({NODE_ENV: 'production'});

var files = [
  path.join(__dirname, 'config.json'),
  path.join(__dirname, 'config.' + conf.get('NODE_ENV') + '.json'),
  path.join(__dirname, 'config.' + conf.get('NODE_ENV') + '.' + conf.get('USER') + '.json')
].filter(fs.existsSync);

console.log('Loading config from files', files);

conf.use('memory', {loadFrom: files});