The site went offline a few hours today. Sorry.
It turns out Ubuntu once again changed a major component and the upgrade path didn’t work as it should to keep the lights on after the upgrade.
I’ve been updating the security settings on the server all around, and one of the things I wanted to do was adding TLSv1.3 support (and nothing before TLSv1.2). For that I needed, it seemed the best option to push forward the Ubuntu server version to the newer LTS version (18.04) and as part of this get a newer NGINX with TLSv1.3 support. That part worked sort of great.
Turns out, however, that Ubuntu switched to Netplan in the new LTS and the migration - on my server completely broke all network connectivity and it had no working network.
Being at DigitalOcean made it easy to get back to the server using the (web) Console from the Web Dashboard for the server, and start looking around. I failed to read the release notes but (ab)using friends from the office, I eventually figured out, it was the NetPlan adoption which did not move the existing interfaces configuration forward, which caused issues.
Building a YAML configuration file was fairly easy, once the issue was identified, but what a bad experience - particularly googling for details on how the IPv6 configuration should be setup was interesting.
Anyway eventually the network was configured for IPv4 and IPv6, and here I am back again.