Fail2ban Error on start

Question

Recently, I have tried restarting Fail2ban and I have received an error, making it impossible to start... The full error I received from systemctl status fail2ban is as follows:

Jan 03 18:27:02 nerdofcode.com systemd[1]: fail2ban.service: Control process exited, code=exited status=255
Jan 03 18:27:02 nerdofcode.com systemd[1]: Failed to start Fail2Ban Service.
Jan 03 18:27:02 nerdofcode.com systemd[1]: fail2ban.service: Unit entered failed state.
Jan 03 18:27:02 nerdofcode.com systemd[1]: fail2ban.service: Failed with result 'exit-code'.
Jan 03 18:27:02 nerdofcode.com systemd[1]: fail2ban.service: Service hold-off time over, scheduling restart.
Jan 03 18:27:02 nerdofcode.com systemd[1]: Stopped Fail2Ban Service.
Jan 03 18:27:02 nerdofcode.com systemd[1]: fail2ban.service: Start request repeated too quickly.
Jan 03 18:27:02 nerdofcode.com systemd[1]: Failed to start Fail2Ban Service.
Jan 03 18:27:02 nerdofcode.com systemd[1]: fail2ban.service: Unit entered failed state.
Jan 03 18:27:02 nerdofcode.com systemd[1]: fail2ban.service: Failed with result 'exit-code'.

The full output of cat /var/log/fail2ban.log is:

2018-01-03 18:06:28,337 fail2ban.server         [25119]: INFO    
Exiting Fail2ban

I would appreciate any suggestions or solutions towards this issue.

Solution

There is a good chance that the error has been logged to /var/log/fail2ban.log however you can also see what the problem is by running fail2ban-client -x start and you will get something descriptive.

In my case it was an exim rejectlog that did not yet exist.

Credit to @bistoco's comment on the question.

Comments

[bistoco]

is that error line from /var/log/fail2ban.log?

[NerdOfCode]

The error is provided from systemctl status fail2ban

[bistoco]

Then check /var/log/fail2ban.log. Hopefully it will give you a detailed trace of the reason of failure.

[bistoco]

This may help

[NerdOfCode]

This has temporarily fixed the issue. But, I'm looking for a long term fix

[bistoco]

That's not a solution, it will help you to identify errors on your config, so you can fix them and then restart the service properly.