Third-party resources (deprecated):
Register a third-party resource type with the API, create/update/query this third-party
type, and write a controller that drives the cluster state based on the changes to
the third-party resources.
Custom Resource Definition (successor of TPR):
Register a custom resource type with the API, create/update/query this custom
type, and write a controller that drives the cluster state based on the changes to
the custom resources.