C library for the MaxMind DB file format http://maxmind.github.io/libmaxminddb/
https://github.com/maxmind/libmaxminddb

MaxMind DB File Format Specification
http://maxmind.github.io/MaxMind-DB/

http://maxmind.github.io/libmaxminddb/
http://maxmind.github.io/libmaxminddb/#example


GeoLite2 Free Downloadable Databases
https://dev.maxmind.com/geoip/geoip2/geolite2/

GeoLite2 Country
http://geolite.maxmind.com/download/geoip/database/GeoLite2-Country.tar.gz

GeoLite2 City
http://geolite.maxmind.com/download/geoip/database/GeoLite2-City.tar.gz


FreeBSD:
cd /usr/ports/net/libmaxminddb && make install clean
[ -d /usr/local/share/GeoIP ] || mkdir -p /usr/local/share/GeoIP
wget http://geolite.maxmind.com/download/geoip/database/GeoLite2-Country.tar.gz -O/tmp/GeoLite2-Country.tar.gz
tar -xz --cd /tmp -f /tmp/GeoLite2-Country.tar.gz $(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb)
mv /tmp/$(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb) /usr/local/share/GeoIP/
rm -rf /tmp/$(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb | xargs dirname) /tmp/GeoLite2-Country.tar.gz


CentOS
yum install -y libmaxminddb libmaxminddb-devel
[ -d /usr/share/GeoIP ] || mkdir -p /usr/share/GeoIP
wget http://geolite.maxmind.com/download/geoip/database/GeoLite2-Country.tar.gz -O/tmp/GeoLite2-Country.tar.gz
tar -xz --directory=/tmp -f /tmp/GeoLite2-Country.tar.gz $(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb)
mv /tmp/$(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb) /usr/share/GeoIP/
rm -rf /tmp/$(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb | xargs dirname) /tmp/GeoLite2-Country.tar.gz


Ubuntu:
apt-get update && apt-get install -y libmaxminddb0 libmaxminddb-dev mmdb-bin
[ -d /usr/share/GeoIP ] || mkdir -p /usr/share/GeoIP
wget http://geolite.maxmind.com/download/geoip/database/GeoLite2-Country.tar.gz -O/tmp/GeoLite2-Country.tar.gz
tar -xz --directory=/tmp -f /tmp/GeoLite2-Country.tar.gz $(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb)
mv /tmp/$(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb) /usr/share/GeoIP/
rm -rf /tmp/$(tar -tzf /tmp/GeoLite2-Country.tar.gz | grep GeoLite2-Country.mmdb | xargs dirname) /tmp/GeoLite2-Country.tar.gz