Let's Encrypt 无法续签

因为疏忽（没有用自动续签，并且忘记手动续签），SSL 过期了， 然后上服务器使用 certbot renew 命令更新证书出现了如下提示

Saving debug log to /var/log/letsencrypt/letsencrypt.log

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Processing /etc/letsencrypt/renewal/域名.conf
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cert is due for renewal, auto-renewing...
Plugins selected: Authenticator standalone, Installer None
Renewing an existing certificate
Attempting to renew cert (域名) from /etc/letsencrypt/renewal/域名).conf produced an unexpected error:
urn:ietf:params:acme:error:rateLimited :: 
There were too many requests of a given type :: Error creating new order :: 
too many failed authorizations recently: see https://letsencrypt.org/docs/rate-limits/. 
Skipping.
All renewal attempts failed. The following certs could not be renewed:
 /etc/letsencrypt/live/域名)/fullchain.pem (failure)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
All renewal attempts failed. The following certs could not be renewed:
  /etc/letsencrypt/live/域名/fullchain.pem (failure)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 renew failure(s), 0 parse failure(s)

IMPORTANT NOTES:
 - The following errors were reported by the server:

   Domain: 域名
   Type:   dns
   Detail: DNS problem: NXDOMAIN looking up A for 域名 -
   check that a DNS record exists for this domain

留意到错误信息那里:

DNS problem: NXDOMAIN looking up A for www.域名 - check that a DNS record exists for this domain

也就是 DNS出问题了，但是很奇怪的是我最近并没有修改过DNS或者 let's encry 的配置。

尝试一

网上大部分都是说DNS问题的，然后我试着 ping 了自己的域名，是能 ping 通的。说明 DNS -> 服务器 这个通道是正常的.

然后是用了 certbot certificates 去查看证书信息

Found the following certs:
  Certificate Name: 域名
    Serial Number: 马赛克
    Domains: 域名 www.域名
    Expiry Date: 过期日期
    Certificate Path: /etc/letsencrypt/live/证书地址
    Private Key Path: /etc/letsencrypt/live/私钥地址

咦？怎么有两个域名，一个带www, 一个不带的（其实是我自己配的）
然后我刚才 ping 的是不带 www 的， 然后再去试一下ping 带 w 的。ping 不通。

难道问题找到了，但是怎么添加 www 的DNS代理呢..

然后上DNS服务商, 加了一行www的配置

DNS配置

重新 ping 了一下，通了。然后重新跑一遍 certbot renew ，成功了!