Flink UDF in Go

Requirements

• Java 8+, 64-bit
• https://github.com/superbear/java-call-go

How to build

Install dependencies

USERNAME={{your github username}} ACCESS_TOKEN={{github personal access token}} mvn -s .m2/settings.xml clean install

Working with the GitHub Apache Maven registry

Build

mvn clean package

This creates a flink-udf-in-go-1.0-SNAPSHOT.jar in the target/ directory.

Test

mvn clean test

Usage

Running the container

docker compose up -d

Executing queries

docker compose run sql-client

Flink SQL> CREATE FUNCTION atoi AS 'github.superbear.flink.udf.scalar.Atoi' LANGUAGE JAVA;
Flink SQL> CREATE FUNCTION toupper AS 'github.superbear.flink.udf.scalar.ToUpper' LANGUAGE JAVA;

Flink SQL> SELECT atoi('123');
Flink SQL> SELECT toupper('hello world');

Flink SQL> exit;

References

• Flink User-defined Functions
• Flink Docker Setup