You need to download geoip2 database manually and setup file path in config.
filter:
- type: geoip2
# (required) geoip2 database file path, default: GeoLite2-City.mmdb
db_path: "geoip2/database/file/path/GeoLite2-City.mmdb"
# (required) ip address field to parse
ip_field: remote_addr
# (optional) parsed geoip info should saved to field, default: geoip
key: geoip