rules_quarkus — Bazel rules for Quarkus framework with build-time augmentation

[kinhluan]

Hey everyone 👋

I wanted to share a project I've been working on: rules_quarkus — Bazel rules for building Quarkus applications.

The problem

Quarkus does heavy build-time processing (called "augmentation") — CDI bean discovery, REST endpoint generation, config injection, etc. This has traditionally been tightly coupled to Maven/Gradle plugins,
making it difficult to use Quarkus in Bazel monorepos.

The approach

Instead of shelling out to Maven, rules_quarkus calls the QuarkusBootstrap API directly within a Bazel action. It constructs the ApplicationModel from Bazel's dependency graph, handling the
separation between runtime and deployment artifacts that Quarkus requires.

The trickiest part was ClassLoader isolation — Quarkus augmentation needs its own classloader hierarchy to avoid conflicts with the build tool's classes.

Quick example

   load("@rules_quarkus//quarkus:defs.bzl", "quarkus_application")

   quarkus_application(
       name = "my-app",
       srcs = glob(["src/main/java/**/*.java"] ),
       runtime_extensions = ["@maven//:io_quarkus_quarkus_arc", ...],
       deployment_extensions = ["@maven//:io_quarkus_quarkus_arc_deployment", ...],
   )

Stack

• Quarkus 3.20.1
• Bazel 7.x with Bzlmod
• Java 21
• Uses rules_jvm_external for Maven dependency resolution

Would love feedback from the community, especially anyone who has tried (or wanted to try) Quarkus with Bazel.

Repo: https://github.com/kinhluan/rules_quarkus