This is an unofficial Heroku buildpack that supports maxminddb ruby gem.
Define GEOIP_DB_PUBLIC_URI ENV variable from where to fetch the files.
A separate process should be placing the files there once a day/week. Depends on the update frequency.
Files should be in .tar.gz format:
❯ tar -tzf ~/Downloads/GeoLite2-City.mmdb.tar.gz
GeoLite2-City_20240319/
GeoLite2-City_20240319/LICENSE.txt
GeoLite2-City_20240319/COPYRIGHT.txt
GeoLite2-City_20240319/GeoLite2-City.mmdb
GeoLite2-City_20240319/README.txt