Packaging Red Hat build of OpenJDK 21 applications in containers
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Chapter 1. Red Hat build of OpenJDK applications in containers
Red Hat build of OpenJDK images have default startup scripts that automatically detect application
JAR files and launch Java. The script’s behavior can be customized using environment variables. For more information, see
/help.md in the container.
The Java applications in the
/deployments directory of the OpenJDK image are run when the image loads.
Containers that contain Red Hat build of OpenJDK applications are not automatically updated with security updates. Ensure that you update these images at least once every three months.
JAR files can be fat JARs or thin JARs.
- Fat JARs contain all of the application’s dependencies.
Thin JARs reference other JARs that contain some, or all, of the application’s dependencies.
Thin JARs are only supported if:
- They have a flat classpath.
All dependencies are JARs that are in the
Chapter 2. Deploying Red Hat build of OpenJDK application in containers
You can deploy Red Hat build of OpenJDK applications in containers and have them run when the container is loaded.
Copy the application
/deploymentsdirectory in the image
For example, the following shows a brief Dockerfile that adds an application called
testubi.jarto the Red Hat build of OpenJDK 21 UBI8 image:
FROM registry.access.redhat.com/ubi8/openjdk-17 COPY target/testubi.jar /deployments/testubi.jar
Chapter 3. Updating Red Hat build of OpenJDK container images
To ensure that an Red Hat build of OpenJDK container with Java applications includes the latest security updates, rebuild the container.
- Pull the base Red Hat build of OpenJDK image.
Deploy the Red Hat build of OpenJDK application. For more information, see Deploying Red Hat build of OpenJDK applications in containers.
The Red Hat build of OpenJDK container with the Red Hat build of OpenJDK application is updated.
- For more information, see Red Hat OpenJDK Container images.
Revised on 2023-11-14 18:22:37 UTC