Creating a Container Image with External Java

This procedure describes how to create a Docker container image that contains your own Java instead of the default BMC-provided image that already contains Java version 21 (OpenJDK).

You need to create your image from another BMC-provided image that does not contain Java. This image has the 9.21.300-k8s tag and is stored in the controlm/helix-agent repository in the Docker Hub.

BMC-provided images are based on AlmaLinux Minimal, which includes a microdnf package manager.

Before You Begin

Ensure that the Linux x86_64 Java package is of a supported version and vendor, as listed in Compatibility with External Java Vendors.

BMC recommends that you use a headless variant of Java, whenever available, to reduce the image footprint and save space.

Begin

1. Create a Dockerfile with the following content:

   FROM controlm/helix-agent:9.21.300-k8s
   ENV BMC_INST_JAVA_HOME=<path to your installed JDK>
   RUN <JDK installation commands>
   RUN ./update_java_home.sh 

   Example

   Dockerfile with Amazon Corretto JDK:

   FROM controlm/helix-agent:9.21.300-k8s
   ENV BMC_INST_JAVA_HOME=/etc/alternatives/java_sdk
   RUN echo "Install Amazon Corretto JDK" \
      && sudo rpm --import https://yum.corretto.aws/corretto.key \
      && sudo curl -L -o /etc/yum.repos.d/corretto.repo https://yum.corretto.aws/corretto.repo \
      && sudo microdnf install -y java-21-amazon-corretto-devel \
      && sudo microdnf clean all \
      && java -version
   RUN ./update_java_home.sh

2. Build an image based on the Dockerfile that you created by running the following command:
   docker build . --tag <image name>
   The image name includes the name of the repository where you want to upload the created image.
   

   Example

   docker build . --tag private_repo/agent-with-amazon-corretto-java

3. Push the image to your private repository by running the following command:
   docker push <image name>
   The image name includes the name of the repository where you want to upload the image.

   Example

   docker push private_repo/agent-with-amazon-corretto-java