1.教程
https://www.vpser.net/build/letsencrypt-certbot.html
http://www.javashuo.com/article/p-hnxfilsj-cn.html
http://www.tuicool.com/articles/ZZrAN32
2.官方文檔
https://certbot.eff.org/#centos6-nginx
https://certbot.eff.org/docs/using.html#webroothtml
還有個坑,網站要開啓容許目錄訪問。nginx