koahub-loader

 // 1.model loader
 var model = loader([
 {
     root: './app/model',
     suffix: '.model.js'
 },
 {
     root: './addon',
     suffix: '.model.js',
     filter: [/\w*\/model\//]
 }
 ]);

 // 2.controller loader
 var app = require('koa')();
 var router = require('koa-router')();
 var controller = loader([
 {
    root: './app/controller',
    suffix: '.controller.js',
    prefix: '/',
 }, {
    root: './addon',
    suffix: '.controller.js',
    prefix: '/addon/',
    filter: [/\w*\/controller\//]
 }
 ]);

 for (var key in controller) {
    router.use(key, controller[key].routes());
 }
 app.use(router.routes());

 // 3.util loader
 var util = loader([
 {
     root: './app/common',
     suffix: '.util.js'
 },
 {
     root: './addon',
     suffix: '.util.js',
     filter: [/\w*\/common\//]
 }
 ]);