- https://github.com/kubernetes-sigs/kustomize/issues/4731: Remove a potential build-time side-effect in ConfigMapGenerator and SecretGenerator, which loaded values from the local environment under some circumstances, breaking kustomize build's side-effect-free promise. While this behavior was never intended, we deprecated it and are announcing it as a breaking change since it existed for a long time. See also the Eschewed...

- Support server-side dry-run in kubectl with --dry-run=server for commands including apply, patch, create, run, annotate,...

- `-- kube-controller-manager`
  `--node-cidr-mask-size-ipv4 int32`     Default: 24. Mask size for IPv4 node-cidr in dual-stack cluster.
`--node-cidr-mask-size-ipv6 int32`     Default: 64. Mask size for IPv6 node-cidr in dual-stack cluster.

    These 2 flags can be used only for dual-stack clusters. For non dual-stack clusters, continue to use  `--node-cidr-mask-size` flag to configure the mask size.

- Respect annotation size limit for server-side apply updates to the client-side apply annotation. Also, fix opt-out of this behavior by setting the client-side apply annotation to the empty string. ([#102105](https://github.com/kubernetes/kubernetes/pull/102105), [@julianvmodesto](https://github.com/julianvmodesto)) [SIG API Machinery]

- Fixed bugs in handling of server-side apply, create, and update API requests for objects containing duplicate items in keyed lists.
  - A `create` or `update` API request with duplicate items in a keyed list no longer wipes out managedFields. Examples include env var entries with the same name, or port entries with the same containerPort in a pod spec.

* Add spec.additionalPrinterColumns to CRDs to define server side printing columns. ([#60991](https://github.com/kubernetes/kubernetes/pull/60991), [@sttts](https://github.com/sttts))
* fix azure file size grow issue ([#64383](https://github.com/kubernetes/kubernetes/pull/64383), [@andyzhangx](https://github.com/andyzhangx))

  - true/strict - perform validation and error the request on any invalid fields in the ojbect. It will attempt to perform server-side validation if it is enabled on the apiserver, otherwise it will fall back to client-side validation.

- Respect annotation size limit for server-side apply updates to the client-side apply annotation. Also, fix opt-out of this behavior by setting the client-side apply annotation to the empty string. ([#102105](https://github.com/kubernetes/kubernetes/pull/102105), [@julianvmodesto](https://github.com/julianvmodesto)) [SIG API Machinery]

- Dynamic Resource Allocation (DRA): client-side validation of a ResourceHandle would have accepted a missing DriverName, whereas server-side validation then would have raised an error. ([#124075](https://github.com/kubernetes/kubernetes/pull/124075), [@pohly](https://github.com/pohly))

  1. When configuring a dual-stack cluster, the user must specify both `--node-cidr-mask-size-ipv4` and `--node-cidr-mask-size-ipv6` to set the per-node IP mask sizes, instead of the previous `--node-cidr-mask-size` flag.
  2. The `--node-cidr-mask-size` flag is mutually exclusive with `--node-cidr-mask-size-ipv4` and `--node-cidr-mask-size-ipv6`.