- Fixed bug in beta aggregated discovery endpoint which caused CRD discovery information to be temporarily missing when an Aggregated APIService with the same GroupVersion is deleted (and vice versa). ([#116770](https://github.com/kubernetes/kubernetes/pull/116770), [@alexzielenski](https://github.com/alexzielenski))

* `kubectl run --env` no longer supports CSV parsing. To provide multiple env vars, use the `--env` flag multiple times instead of having env vars separated by commas. E.g. `--env ONE=1 --env TWO=2` instead of `--env ONE=1,TWO=2`. ([#47460](https://github.com/kubernetes/kubernetes/pull/47460), [@mengqiy](https://github.com/mengqiy))

- Added a new container based image for running e2e tests ([#69368](https://github.com/kubernetes/kubernetes/pull/69368), [@dims](https://github.com/dims))
- The `LC_ALL` and `LC_MESSAGES` env vars can now be used to set desired locale for `kubectl` while keeping `LANG` unchanged. ([#69500](https://github.com/kubernetes/kubernetes/pull/69500), [@m1kola](https://github.com/m1kola))

tes.io/pod` and `container.seccomp.security.alpha.kubernetes.io/...` annotations are now deprecated, and will be removed in Kubernetes v1.22.0. Right now, an automatic version skew handling will convert the new field into the annotations and vice versa. This means there is no action required for converting existing workloads in a cluster.

You can find more information about how to restrict container system calls with seccomp in the new [documentation page on Kubernetes.io][seccomp-docs]...

* Return container command exit codes in kubectl run/exec ([#26541](https://github.com/kubernetes/kubernetes/pull/26541), [@sttts](https://github.com/sttts))
* Fix kubectl describe to display a container's resource limit env vars as node allocatable when the limits are not set ([#29849](https://github.com/kubernetes/kubernetes/pull/29849), [@aveshagarwal](https://github.com/aveshagarwal))

      * Added exported env vars to kubectl plugins so that plugin developers have access to global flags, namespace, the plugin descriptor and the full path to the caller binary.

  * Enhancement