https://operatorframework.io/
https://operatorframework.io/what/

https://github.com/operator-framework

https://sdk.operatorframework.io/
https://sdk.operatorframework.io/docs/

https://operatorhub.io/
    https://operatorhub.io/operator/argocd-operator
    https://github.com/argoproj-labs/argocd-operator

https://github.com/operator-framework/operator-registry

https://javaoperatorsdk.io/
https://javaoperatorsdk.io/docs/getting-started
https://github.com/operator-framework/java-operator-sdk
    2022
    https://www.youtube.com/watch?v=CvftaV-xrB4
    https://developers.redhat.com/articles/2022/03/22/write-kubernetes-java-java-operator-sdk-part-2
    https://developers.redhat.com/articles/2022/02/15/write-kubernetes-java-java-operator-sdk