[beta] User-provided apiservers can be aggregated (served along with) the rest of the Kubernetes API. See [Extending the Kubernetes API with the aggregation layer](https://kubernetes.io/docs/concepts/api-extension/apiserver-aggregation/), [Configure the aggregation layer](https://kubernetes.io/docs/tasks/access-kubernetes-api/configure-aggregation-layer/), and [Setup an extension API server](https://kubernetes.io/docs/tasks/access-kubernetes-api/setup-extension-api-server/).

* [alpha] Adding...