node之koa2

koa(可参考：https://www.cnblogs.com/wisewrong/p/8202707.html)

npm i koa-generator -g
koa2 projectName
cd projectName && yarn

koa跨域（koa2-cros模块）: https://www.npmjs.com/package/koa2-cors

var cors = require('koa-cors');
var app = koa();
 
app.use(cors());

mongodb (mongoose模块)

加密（crypto模块）https://www.liaoxuefeng.com/wiki/001434446689867b27157e896e74d51a89c25cc8b43bdb3000/001434501504929883d11d84a1541c6907eefd792c0da51000

const crypto = require('crypto');
//md5加密
let createMd5 = str =>{
    let hash = crypto.createHash('md5');
    return hash.update(str).digest('hex');
}
console.log(createMd5(456))

时间（moment模块）http://momentjs.cn/docs/