Still, an automated process that has been running unattended for three years suddenly stopping working has never caused a problem, right?
It turns out some things have changed with LetsEncrypt in the last three years. Like, everything. Everything. Even the name. Now the thing I want is called Certbot. Fortunately (and against the trend in modern days) it has improved with time. Now there are packages and guides! Sadly, migration is going to be worse than setting things up in the first place. It's installing new software then making sure it's renewing certs generated in the old way, in the old place.
Sigh, here we go.
So I followed the install section of this guide then ran:
sudo certbot renewAnd it ... just worked?! I don't understand. This is not computing.
Ok, I need to fix the cron too. That'll cause problems.
export PATH=<boring path stuff> && /another/path/letsencrypt/letsencrypt-auto renew >> /path/to/logs/renew.logChange to:
/usr/bin/certbot renew >> /path/to/logs/renew.logAnd ... that appears to just work too?!
Amazing. It looks like some things do get better.