Support deploying v1alpha2 and v1alpha1 controllers simultaneously

[jlewi]

To support development of v1alpha2 and migration to the v1alpha2 API, we'd like to make it possible to deploy controllers for v1alpha1 and v1alpha2 in the same cluster.

The controllers should only claim/operate on API objects with the correct version.

[jlewi]

It looks like informers are scoped to specific versions.

https://github.com/kubeflow/tf-operator/blob/master/pkg/controller/controller.go#L110
https://github.com/kubeflow/tf-operator/blob/master/pkg/controller.v2/controller.go#L205

So I think the different controllers are already scoped to specific versions. And no additional work is needed.

I will open up a separate issue to add an appropriate ksonnet package.

[jlewi]

It looks like K8s doesn't support deploying multiple versions of the resource simultaneously;
see kubernetes/enhancements#544

One workaround is to create a resource with a different name.

[gaocegege]

Yeah, I meet the same problem.

[gaocegege]

I am closing the issue since we know it is not supported by kubernetes.