See CRC notes at the end of the Readme, that's the new thing.

This example was derived from reading this blog post: https://www.instana.com/blog/writing-a-kubernetes-operator-in-java-part-1/

operator-example project

This project uses Quarkus, the Supersonic Subatomic Java Framework.

If you want to learn more about Quarkus, please visit its website: https://quarkus.io/ .

Running the application in dev mode

You can run your application in dev mode that enables live coding using:

./mvnw quarkus:dev

Packaging and running the application

The application can be packaged using ./mvnw package. It produces the operator-example-1.0-SNAPSHOT-runner.jar file in the /target directory. Be aware that it’s not an über-jar as the dependencies are copied into the target/lib directory.

The application is now runnable using java -jar target/operator-example-1.0-SNAPSHOT-runner.jar.

Creating a native executable

You can create a native executable using: ./mvnw package -Pnative.

Or, if you don't have GraalVM installed, you can run the native executable build in a container using: ./mvnw package -Pnative -Dquarkus.native.container-build=true.

You can then execute your native executable with: ./target/operator-example-1.0-SNAPSHOT-runner

If you want to learn more about building native executables, please consult https://quarkus.io/guides/building-native-image.

Notes about deploying on CodeReadyContainers (CRC) [CRC v1.10.0/OpenShift 4.4.3]

The jib extension has been added to this project to allow for building the image and pushing. You can avoid having to push/pull to a remote registry if you are running CRC locally since it includes a built-in registry.

It is easiest to locally deploy the operator created if the project/NameSpace and ServiceAccount match up:

So if building and pushing with this:

./mvnw clean package -Pnative -Dquarkus.native.container-build=true -Dnative-image.xmx=5g -Dquarkus.container-image.build=true -Dquarkus.container-image.registry=default-route-openshift-image-registry.apps-crc.testing -Dquarkus.container-image.group=default
docker login -u kubeadmin -p $(oc whoami -t) default-route-openshift-image-registry.apps-crc.testing
docker push default-route-openshift-image-registry.apps-crc.testing/default/operator-example:1.0-SNAPSHOT

The quarkus.container-image.group matches the default project in CRC and the registry set by: quarkus.container-image.registry matches the external registry route that CRC has.

There are corresponding entries in the src/main/ocp/operator-example.deployment.yaml spec.template.spec.containers.image field, but pointing to the internal registry: image-registry.openshift-image-registry.svc:5000/default/operator-example:1.0-SNAPSHOT

Setup and install for OpenShift can be somewhat automated by calling:

export DEPLOY_NAMESPACE=default
make apply
make deploy

If all goes well you'll have a deployment with a pod up that ran the Quarkus operator on startup and listed all the pods running in default project. The log for the operator-example.* pod in the operator-example deployment in the default project should list at least itself for running pods.