Dietpi: General | Install Fail2Ban for all DietPi systems, as default.

[Fourdee]

http://fuzon.co.uk/phpbb/viewtopic.php?f=9&t=123&p=436#p428

NB: prevents brute-force attacks by banning IP address

[Fourdee]

The following NEW packages will be installed:
fail2ban libpython-stdlib libpython2.7-minimal libpython2.7-stdlib
libsqlite3-0 mime-support python python-minimal python2.7 python2.7-minimal
0 upgraded, 10 newly installed, 0 to remove and 0 not upgraded.
Need to get 4,377 kB of archives.
After this operation, 16.6 MB of additional disk space will be used.

Pretty chunky due to python pre-reqs, will add as an optional installation option in DietPi-Software.

[Fourdee]

NB: Requires rsyslog (so SSH can log to /var/log/auth.log via syslog), and SSh server logging enabled.

[Fourdee]

Done, available in next release (v97).

[joaofl]

@Fourdee
I tried to install it today and it did not work out of the box. Investigating, I got to know rsyslog was required, and it is still not on the install script. Should I add it?

[MichaIng]

@joaofl
rsyslog is not required as long as journald is used to check for SSH authentication failures. And our installer pre-configures fail2ban to do so.

However does the installer break at some point? Will try it on test system.

---

Indeed some changes have been done to the Stretch fail2ban, staring with the logging system from numerical:

# Option: loglevel
# Notes.: Set the log level output.
#         1 = ERROR
#         2 = WARN
#         3 = INFO
#         4 = DEBUG
# Values: [ NUM ]  Default: 1
#
loglevel = 3

to words with more levels:

# Option: loglevel
# Notes.: Set the log level output.
#         CRITICAL
#         ERROR
#         WARNING
#         NOTICE
#         INFO
#         DEBUG
# Values: [ LEVEL ]  Default: ERROR
#
loglevel = INFO

Maintainer defaults are what we want, will switch to keep the config file, leave the logging mode and only adjust the settings that we need (syslog/journald).

[MichaIng]

@joaofl
It is really only the loglevel settings that you need to change (or remove to revert to defaults):
In /etc/fail2ban/fail2ban.log:
loglevel = 3 => loglevel = INFO

I reworked our installed a bid and fixed this: https://github.com/MichaIng/DietPi/pull/2727

[joaofl]

@MichaIng Thanks for the quick fix. I'll give it a try soon.