A short note about a failure to renew the LE certs for f3.forgefriends.org and a few others. LE sent mails about the approaching renewal.
It was caused by a lost port forward for 80 (how was it lost I have no idea). The solution was to restart the host that runs the reverse proxy and carries all requests to port 80. It installs the port forward when it starts, as indicated in the README file of the ~/.enough/forgefriends.lan configuration.
$ virsh destroy proxy-host
$ virsh start proxy-host
$ certbot renew
...
Congratulations, all renewals succeeded. The following certs have been renewed:
/etc/letsencrypt/live/chat.fedeproxy.eu/fullchain.pem (success)
/etc/letsencrypt/live/chat.forgefriends.org/fullchain.pem (success)
/etc/letsencrypt/live/cloud.fedeproxy.eu/fullchain.pem (success)
/etc/letsencrypt/live/cloud.forgefriends.org/fullchain.pem (success)
/etc/letsencrypt/live/f3.forgefriends.org/fullchain.pem (success)
/etc/letsencrypt/live/fedeproxy.eu/fullchain.pem (success)
/etc/letsencrypt/live/forgefriends.org/fullchain.pem (success)
/etc/letsencrypt/live/format.forgefriends.org/fullchain.pem (success)
/etc/letsencrypt/live/forum.fedeproxy.eu/fullchain.pem (success)
/etc/letsencrypt/live/forum.forgefriends.org/fullchain.pem (success)
/etc/letsencrypt/live/lab.fedeproxy.eu/fullchain.pem (success)
/etc/letsencrypt/live/lab.forgefriends.org/fullchain.pem (success)
/etc/letsencrypt/live/pages.forgefriends.org/fullchain.pem (success)