Quarkus Magic: Code Manipulation with Quarkus Extensions

Quarkus is a Java framework that can not only compile an application to an executable JAR, but also to a native image using GraalVM. These native images do not require a JVM at runtime, and are well suited for putting them into a minimal Docker image to be deployed in a Kubernetes cluster.

Under the hood, not all Java features are supported 1-to-1 on the native image. Quarkus makes it look like developers can use well-known Java libraries without any modifications, but internally Quarkus implements an extension framework to modify code at compile time to make libraries compatible with the native image.

In this talk we present how to write your own Quarkus extension and what you can do with these extensions. Use cases range from making libraries compatible, to optimizing runtime performance, to injecting new functionality.