`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...

- **Auth**
  - [alpha] Further polishing of the Role-based access control alpha API including a default set of cluster roles. ([docs](http://kubernetes.io/docs/admin/authorization/)) ([kubernetes/features#2](https://github.com/kubernetes/enhancements/issues/2))

    it keeps your `HeldCertificate` and its chain. On the client it keeps the root certificates
    that are trusted to sign a server's certificate chain. `HandshakeCertificates` also works with
    mutual TLS where these roles are reversed.

    These classes make it possible to enable HTTPS in MockWebServer in [just a few lines of
    code][https_server_sample].

    /** The key of the message: Query */
    public static final String LABELS_Q = "{labels.q}";

    /** The key of the message: Roles */
    public static final String LABELS_ROLES = "{labels.roles}";

    /** The key of the message: Suggest Search Log */
    public static final String LABELS_SUGGEST_SEARCH_LOG = "{labels.suggestSearchLog}";

* 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))

* 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:

- 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))

  - 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))...

  `Boots and shoes under the sea,' the Gryphon went on in a deep
voice, `are done with a whiting.  Now you know.'

  `And what are they made of?' Alice asked in a tone of great
curiosity.

  `Soles and eels, of course,' the Gryphon replied rather
impatiently:  `any shrimp could have told you that.'

  `If I'd been the whiting,' said Alice, whose thoughts were

- The `BalancedAllocation` plugin now skips all best-effort (zero-requested) pods. ([#130260](https://github.com/kubernetes/kubernetes/pull/130260), [@Bowser1704](https://github.com/Bowser1704))
- The following roles have had `Watch` added to them (prefixed with `system:controller:`):
  
  - `cronjob-controller`
  - `endpoint-controller`
  - `endpointslice-controller`
  - `endpointslicemirroring-controller`