koa 项目常用库：

1. koa-body https://github.com/dlau/koa-body; koa-router https://github.com/alexmingoia/koa-router; koa-json https://github.com/koajs/json; koa-static https://github.com/koajs/static; koa-timeout https://github.com/wejendorp/koa-timeout; koa-session https://npm.taobao.org/package/koa-session; 持久存储， koa-session-redis3
   redis https://npm.taobao.org/package/redis; ioredis : https://npm.taobao.org/package/ioredis; 推荐用这个，直接支持promise moment : http://momentjs.com/docs/ 日期操作的一个库
2. node-bunyan 一个日志打印的模块 https://github.com/trentm/node-bunyan
3. bluebird https://npm.taobao.org/package/bluebird http://bluebirdjs.com/docs/getting-started.html
4. co https://npm.taobao.org/package/co
5. lodash http://lodashjs.com/docs/
6. sequelize http://docs.sequelizejs.com/en/latest/ 注意，这个模块以来pg模块，专门操作postgresql数据库的node客户端
7. mongoose https://npm.taobao.org/package/mongoose http://mongoosejs.com/
8. 支持koa的mongdb orm库： http://mongorito.com/
9. koa-request https://npm.taobao.org/package/koa-request
10. config https://npm.taobao.org/package/config 一个组织项目配置文件的的模块