Broken Fail2Ban version in Linode Repo for Ubuntu 24.04

This appears to be a known bug for Ubuntu 24.04 LTS users since asynchat was removed from the upstream Python3 library. For visibility into what this looks like, here is a snippet of the systemctl status after installing Fail2Ban:

systemctl status fail2ban.service:

× fail2ban.service - Fail2Ban Service
     Loaded: loaded (/usr/lib/systemd/system/fail2ban.service; enabled; preset: enabled)
     Active: failed (Result: exit-code) since Wed 2024-05-22 15:50:53 UTC; 4s ago
   Duration: 112ms
       Docs: man:fail2ban(1)
    Process: 3606 ExecStart=/usr/bin/fail2ban-server -xf start (code=exited, status=255/EXCEPTION)
   Main PID: 3606 (code=exited, status=255/EXCEPTION)

May 22 15:50:53 localhost fail2ban-server[3606]: 2024-05-22 15:50:53,483 fail2ban                [3606]: ERROR   No module named 'asynchat'

I was able to fix the issue by entering the following commands:

wget https://launchpad.net/ubuntu/+source/fail2ban/1.1.0-1/+build/28291332/+files/fail2ban_1.1.0-1_all.deb

sudo dpkg -i fail2ban_1.1.0-1_all.deb

For more information about this process, see the following blog page where I found this work-around:

• Fail2ban Workaround for Ubuntu 24.04

That's great thank you. From a security point, an official release would be better from the standard Linode repo now that Fail2Ban have updated the version, rather than a script from a site we are not aware of?

You can resolve the Fail2Ban issue on Ubuntu 24.04 by removing the current version, adding a PPA repository with a working version, and reinstalling. Run: sudo apt remove fail2ban, sudo add-apt-repository ppa:acraig/fail2ban, sudo apt update, and sudo apt install fail2ban. This should fix the missing dependencies problem.