- Added support for CEL expressions with escaped names in the structured authentication config. Using `[...]` to access claims or user data was recommended when names contained characters that would otherwise need escaping. CEL optionals with `?` could be used where has was not applicable — for example, `claims[?"kubernetes.io"]` or `user.extra[?"domain.io/foo"]`. ([#131574](https://github.com/kubernetes/kubernetes/pull/131574), [@enj](https://github.com/enj)) [SIG API Machinery...

- Introduce support for CEL optionals (see [CEL spec proposal 246](https://github.com/google/cel-spec/wiki/proposal-246)).
  This feature will not be fully enabled until a future Kubernetes release (likely to be v1.29), but is added in v1.28 to enable

- kubeadm: JoinConfiguration now houses the discovery options in a nested Discovery structure, which in turn has a couple of other nested structures to house more specific options (BootstrapTokenDiscovery and FileDiscovery) ([#67763](https://github.com/kubernetes/kubernetes/pull/67763), [@rosti](https://github.com/rosti))

* Pipe get options to storage ([#37693](https://github.com/kubernetes/kubernetes/pull/37693), [@wojtek-t](https://github.com/wojtek-t))
* add a configuration for kubelet to register as a node with taints ([#31647](https://github.com/kubernetes/kubernetes/pull/31647), [@mikedanese](https://github.com/mikedanese))

- Use omitempty for optional Job Pod Failure Policy fields ([#126046](https://github.com/kubernetes/kubernetes/pull/126046), [@mimowo](https://github.com/mimowo)) [SIG Apps]

### Bug or Regression

rate limit is switched to per-client. A set of new rate limit configure options are introduced, including routeRateLimit, SubnetsRateLimit, InterfaceRateLimit, RouteTableRateLimit, LoadBalancerRateLimit, PublicIPAddressRateLimit, SecurityGroupRateLimit, VirtualMachineRateLimit, StorageAccountRateLimit, DiskRateLimit, SnapshotRateLimit, VirtualMachineScaleSetRateLimit and VirtualMachineSizeRateLimit. The original rate limit options would be default values for those new client's rate limiter. ([#8651...

*   You can now add "options" to the host's /etc/resolv.conf (or --resolv-conf), and they will be copied into pod's resolv.conf when dnsPolicy is Default. Being able to customize options is important because it is common to leverage options to fine-tune the behavior of DNS client. ([#54773](https://github.com/kubernetes/kubernetes/pull/54773),[ @phsiao](https://github.com/phsiao))...

#### Storage

* [stable] Mount options

  * The ability to specify mount options for volumes is moved from beta to stable.

  * A new `MountOptions` field in the `PersistentVolume` spec is available to specify mount options. This field replaces an annotation.

  * A new `MountOptions` field in the `StorageClass` spec allows configuration of mount options for dynamically provisioned volumes.

Kubeadm: Automate certificate copy between control planes in HA setups

- Joining control plane nodes to a HA cluster can now be simplified by enabling the optional automatic copy of certificates from an existing control plane node.
- You can now use `kubeadm init --experimental-upload-certs` and `kubeadm join --experimental-control-plane --certificate-key`.

- EmptyDir memory backed volumes are sized as the minimum of pod allocatable memory on a host and an optional explicit user provided value. ([#100319](https://github.com/kubernetes/kubernetes/pull/100319), [@derekwaynecarr](https://github.com/derekwaynecarr)) [SIG Node]