The operating system my web server runs on is (include version): ubuntu20.04
I can login to a root shell on my machine (yes or no, or I don't know): yes
I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): certbot 1.32.2
So, i have a few subdomains on my server. And all of them work fine with certbot ssl. But when i added this domain, ran sudo a2ensite, it does not want to show up in the certbot options. I checked, and the website works, and the file is in sites-enabled. Does anybody know why this happens?
Underscores are valid in "domain names" (things in DNS) but not in "host names" (systems that can have a URL). So certificates can't have them either, since certificates are supposed to be for host names. This quirk actually I think is why a lot of the non-hostname records in DNS use underscores (_dmarc, _acme-challenge, etc.), so that they're guaranteed not to conflict with an actual host's name.