Fail2Ban Data Tools

Small utilities to extract daily ban counts from Fail2Ban logs into a CSV and plot them.

Dependencies

The plotting script requires Matplotlib.

On Debian/Ubuntu you can install it with:

sudo apt update && sudo apt install -y python3-matplotlib

Usage

generate_bans_summary.py

Reads /var/log/fail2ban.log* (plain and compressed) and writes a CSV file with the number of bans per day and per jail.

Run:

python3 generate_bans_summary.py

This generates a CSV file (by default bans_summary.csv) with contents like:

date,All jails,sshd,nginx-forbidden,postfix
2025-07-28,8,5,3,0
2025-07-29,58,38,18,2
2025-07-30,66,49,13,4
...

plot_bans.py

Reads the CSV generated by the previous script and produces a line chart.

Run:

python3 plot_bans.py

This generates an image (by default bans_summary.png) similar to:

Other parameters

Both scripts support other parameters, for instance:

python3 generate_bans_summary.py -o file.csv
python3 plot_bans.py -i file.csv -o file.png --width 12 --heigh 6 --dpi 100

You can see all available options by running:

python3 generate_bans_summary.py --help
python3 plot_bans.py --help

License

MIT