Some useful info:
https://www.digitalocean.com/community/tutorials/how-to-protect-an-nginx-server-with-fail2ban-on-ubuntu-22-04
https://linux-notes.org/ustanovka-fail2ban/
https://github.com/Bebef/fail2ban-filter.d
https://stackoverflow.com/questions/19794107/fail2ban-error-can´t-ban-with-lighttpssd-auth
https://easyengine.io/tutorials/nginx/fail2ban/
Check who’s banned:
fail2ban-client status JAILNAME
fail2ban alerts sent to a Rocket.Chat channel:
https://forums.rocket.chat/t/fail2ban-and-rocket-chat-integration/2544
Incremental bantime:
https://habr.com/ru/post/238303/
Check how filter works:
fail2ban-regex /var/log/somelog.log /etc/fail2ban/filter.d/somefilter.conf
Add –print-all-missed or –print-all-matched to see missed and matched lines.