Micronaut Layered Images Proof-Of-Concept

This repository demonstrates building layered images with Micronaut.

Prerequisites

1. A GraalVM build with the Micronaut Hack patch applied, PR 18329 using:

cd graal/vm
mx --env svm build
mx --env svm graalvm-home

2. make sure you have a JDK 21 installed

Prepare the SDK repository

The custom Micronaut build will use a temporary repository containing the snapshot GraalVM SDK. To generate this repository, do the following:

cd graal/sdk
mx build
mx maven-deploy --licenses UPL,BSD-new,GPLv2-CPE foo file:///tmp/repo

This will create a Maven repository with the artifacts under /tmp/repo.

Deploy a custom Micronaut build

1. git clone git@github.com:micronaut-projects/micronaut-core.git
2. cd micronaut-core
3. git checkout cc/layered-images-4.5
4. export JAVA_HOME=/path/to/your/java-21 and export GRAALVM_HOME=/path/to/your/patched/graalvm-jdk
5. ./gradlew pTML

The last step will build Micronaut 4.5.3 with a patch which allows running with layered images and publish the artifacts in the local Maven repository. That custom version is named 4.5.3-li.

Run the build

Now everything should be available for this project to run. Make sure to:

1. export JAVA_HOME=/path/to/your/java-21
2. export GRAALVM_HOME=/path/to/your/patched/graalvm-jdk

Then you should be able to run the application without layered images support by running:

./gradlew nativeRun

And with layered images support by running:

./gradlew nativeCompile --use-layers nativeRun