Koa2 的安装运行记录（二）
参考 ：koa2-boilerplate https://github.com/superalsrk/koa2-boilerplate
Ajax Login and Ajax Logout in Koa2, based on koa-passport and passport-local
https://github.com/koajs/koa/wiki 有中间件列表
1、
二、Logging 中间件：
1）(推荐) concurrency-logger - logging requests concurrently and in context
https://github.com/PabloSichert/concurrency-logger
2）、 koa-logger - development style logger
安装：npm install koa-logger --save-dev
代码中增加：
var logger = require('koa-logger')
app.use(logger())
功能类似下列函数：
app.use(async (ctx, next) => {
const start = new Date();
await next();
const ms = new Date() - start;
console.log(`${ctx.method} ${ctx.url} - ${ms}ms`);
});
3）（暂不考虑） koa-log4 - a wrapper for log4js-node which supports koa middleware
