PyFilter aims to filter out all of the requests that are not legitimate to your server, and blocks them if too many are sent. It works by reading log files and checking if a failed request has came from the same IP address within a user configurable amount of time and adding rules to the firewall if too many attempts have been captured.
By default PyFilter is configured to read from /var/log/auth.log for incoming SSH requests, however there are options for Apache, Nginx and MySQL too.
PyFilter uses a database to store all the banned ip addresses to ensure ips arent added more than once. PyFilter currently supports sqlite and redis, by default it is setup to use sqlite so no installation of a redis server is needed. However redis has support for cross server ban syncing.