strict makes /run read-only, which blocks ufw's /run/ufw.lock and
cannot be whitelisted via ReadWritePaths (the file does not exist).
full still protects /usr and /etc while leaving /run and /var writable,
so only /etc/ufw needs an explicit write path.
- log to journald via fail2ban.local (logtarget is a fail2ban.conf option,
not jail.local) so the server can start without /var/log write access
- create the socket dir via RuntimeDirectory=fail2ban instead of a
non-creating ReadWritePaths entry
- add ufw write paths so bans persist under the read-only namespace
- manage override.conf unconditionally and restart on change
Clément Désiles