An example of how you can configure CDS and Spring AOT with Gradle and Jib

This is a simple example of how you can make your application start-up time more efficient with the following technologies:

• Spring Boot 3.3.+
• Spring AOT
• Application CDS
• Jib
• Gradle build tool

It's a follow-up to Sebastien's demo app based on maven

Please watch the video from Spring I/O 2024 to know more about the CDS technology.

How to build

./build-cds.sh

How to run

docker run spring-boot-aot-cds-gradle-jib-example:latest

Expect the start-up time is minimal w/o usage of GraalVM

Troubleshooting and hits

• Read the general Jib CDS issue for the details and stories of others
• Currently, JIB doesn't allow extending jib.container.jvmFlags so you have to override all of them, see the issue
• You must run the actual image in order to pass by potential errors due to a wrong CDS archive
• Setup Spring runtime environment as much as close to the actual runtime environment, i.e. set the same properties for the instrumentation run (cds preparation) as you have in the actual runtime environment
  • e.g. properties like SPRING_PROFILES_ACTIVE=prod it's crucial to prebuild the AOT classes the same way they initialize on the actual environment
• Make sure build/libs/cds/application.jsa exists before you build the final image
• The JVM runtime flag -Xshare:on will break (stop) the deployment if the CDS archive doesn't exist, use it wisely on production