Dang, my setup was broken by the failed Certbot run. 😢
Phew. Took me a while to migrate everything properly, but it's all done now.
On the way, I found out that we're currently not backing up the uploaded files in mediawiki's images directory, and we're also not moving them to a new folder in case the wiki itself is upgraded to a new version (which creates a whole new mediawiki directory in /var/www).
However, I still can't merge, because some updated cookbook deps were missing, and our certbot recipe doesn't work with Ubuntu 20.04, because the certbot authors decided to switch to effing snap packages. :/
@greg I think I have pushed everything we did now, but I may have lost a small thing somewhere. We'll see when we finish up the move, unless you already notice something missing.
(Kredits label added here, because I forgot it in the PR. We need something akin to the GitHub bot that doesn't allow merging without one.)