What ports are needed to be open?

[SemoTech]

Can this work with just port 443 (HTTPS) open through the firewall and pointed to the ESXi host, or does it need both 80 (HTTP) and 443 (HTTPS) open?

[Churro]

It needs port 80 as well. Let's Encrypt relies on this port to do a validation, see https://letsencrypt.org/docs/allow-port-80/

[Churro]

No, this plugin doesn't interfere with port mappings. It only adds an HTTP route to handle Let's Encrypt's .well-known/acme-challenge requests. Let's Encrypt requests port 80 specifically, and therefore this port needs to be reachable.

[jacobswin]

Is that possible to use any other port as the 80 and 443 is blocked by ISP?

[Churro]

No, not possible. This isn't a limitation of this plugin but enforced by Let's Encrypt itself.

[jacobswin]

Uh, I understand. If the script can run by DNS challenge, that will be great!

[Churro]

I'm with you but that's quite tricky, unfortunately -> see #2