Type: connection
Detail: Fetching
http://cos.xxxx.com/.well-known/acme-challenge/XepW0zlg4iGqysU59Mg4nuPU_HaYpwbLkx6qDxGCncY:
Timeout during connect (likely firewall problem)
To fix these errors, please make sure that your domain name was
entered correctly and the DNS A/AAAA record(s) for that domain
contain(s) the right IP address. Additionally, please check that
your computer has a publicly routable IP address and that no
firewalls are preventing the server from communicating with the
client. If you're using the webroot plugin, you should also verify
that you are serving files from the webroot path you provided.
错误原因：
需要cd到home才可以，即 cd ~
然后再执行 sudo cerbot --nginx
