passed a file which contains RBAC roles, rolebindings, clusterroles, or
  clusterrolebindings, this command computes covers and adds the missing rules.
  The logic required to properly apply RBAC permissions is more complicated
  than a JSON merge because you have to compute logical covers operations between
  rule sets. This means that we cannot use `kubectl apply` to update RBAC roles

- The built-in system:csi-external-provisioner and system:csi-external-attacher cluster roles are removed as of 1.17 release ([#84282](https://github.com/kubernetes/kubernetes/pull/84282), [@tedyu](https://github.com/tedyu))

* Kubernetes now supports up to 5,000 nodes via etcd v3, which is enabled by default.
* [Role-based access control (RBAC)](https://kubernetes.io//docs/admin/authorization/rbac) has graduated to beta, and defines secure default roles for control plane, node, and controller components.
* The [`kubeadm` cluster bootstrap tool](https://kubernetes.io/docs/getting-started-guides/kubeadm/) has graduated to beta. Some highlights:

* Fix credentials providers for docker sandbox image. ([#51870](https://github.com/kubernetes/kubernetes/pull/51870), [@feiskyer](https://github.com/feiskyer))
* Fix security holes in GCE metadata proxy. ([#51302](https://github.com/kubernetes/kubernetes/pull/51302), [@ihmccreery](https://github.com/ihmccreery))

* Fix SelectorSpreadPriority scheduler to match all selectors when distributing pods. ([#72801](https://github.com/kubernetes/kubernetes/pull/72801), [@Ramyak](https://github.com/Ramyak))
* Add bootstrap service account & cluster roles for node-lifecycle-controller, cloud-node-lifecycle-controller, and cloud-node-controller.   ([#72764](https://github.com/kubernetes/kubernetes/pull/72764), [@andrewsykim](https://github.com/andrewsykim))

  - The built-in `system:csi-external-provisioner` and `system:csi-external-attacher` cluster roles are deprecated and will not be auto-created in a future release. CSI deployments should provide their own RBAC role definitions with required permissions. ([#69868](https://github.com/kubernetes/kubernetes/pull/69868), [@pohly]( https://github.com/pohly))...

* Corrected a race condition in bootstrapping aggregated cluster roles in new HA clusters ([#63761](https://github.com/kubernetes/kubernetes/pull/63761), [@liggitt](https://github.com/liggitt))

`system:aggregate-to-edit` role no longer includes write access to the Endpoints API. For new Kubernetes 1.22 clusters, the `edit` and `admin` roles will no longer include that access in newly created Kubernetes 1.22 clusters. This will have no affect on existing clusters upgrading to Kubernetes 1.22. To retain write access to Endpoints in the aggregated `edit` and `admin` roles for newly created 1.22 clusters, refer to https://github.com/kubernetes/website/pull/29025. ([#103704](https://github.com/kubernet...

- Warn instead of fail when creating Roles and ClusterRoles with custom verbs via kubectl ([#92492](https://github.com/kubernetes/kubernetes/pull/92492), [@eddiezane](https://github.com/eddiezane)) [SIG CLI]

- `kubectl create token` can now be used to request a service account token, and permission to request service account tokens is added to the `edit` and `admin` RBAC roles ([#107880](https://github.com/kubernetes/kubernetes/pull/107880), [@liggitt](https://github.com/liggitt))