Restricted CRD API group "k8s.io"

[elanv]

Controller-tools 0.4.1, which fixes the issue #311 , has been released. However, this only applies to CRD v1. (Now we use v1beta1.)

Not only that, but CRD v1 restricts the "k8s.io" API domain for custom resources. We use API group domain "flinkoperator.k8s.io", so it is likely that should be approved to use or the domain needs to be changed.

Note: https://github.com/kubernetes/enhancements/pull/1111

Originally posted by @elanv in https://github.com/GoogleCloudPlatform/flink-on-k8s-operator/issues/311#issuecomment-736597016

[functicons]

I think it's okay to use k8s.io if that's the only option.

[elanv]

@functicons It would be a good idea to update the CRD version to v1 to fix various CRD issues and apply the operator to the latest kubernetes. To do this, it seems that the operator API domain need to be approved from the kubernetes community. Do you have any plans about it? If not, the domain must be changed. Which do you prefer?

[elanv]

@functicons In addition, updating the controller-tools will reduce the default webhook and default test code, which will help keep the operator code simpler. In order to improve and fix various related issues, I would like to be able to simultaneously update the CRD version to v1 and the controller-tools to the latest. Let me know if you have any idea.