KSQL example UDF for looking up a City for an IP address.
You'll need to supply your own GeoLite database, specify it's location using the function.getcityforip.geolite.db.path
property in your ksql-server.properties before starting KSQL.
mvn clean package
and move the jar target/ksql-udf-geoip-1.0-SNAPSHOT-jar-with-dependencies.jar
into the ext/
directory in your KSQL installation.
SELECT ip, getcityforip(ip) from eventstream;