- Ephemeral containers have been added in alpha. These temporary containers can be added to running pods for purposes such as debugging, similar to how `kubectl exec` runs a process in an existing container. Also like `kubectl exec`, no resources are reserved for ephemeral containers and they are not restarted when they exit. Note that container namespace targeting is not yet implemented, so [process namespace shari...

- Kubelet: fix race condition in pluginWatcher ([#93622](https://github.com/kubernetes/kubernetes/pull/93622), [@knight42](https://github.com/knight42)) [SIG Node]
- Kuberuntime security: pod sandbox now always runs with `runtime/default` seccomp profile

   ([#117024](https://github.com/kubernetes/kubernetes/pull/117024), [@sanposhiho](https://github.com/sanposhiho))

* hyperkube: fix build for 3rd party registry (again) ([#28489](https://github.com/kubernetes/kubernetes/pull/28489), [@liyimeng](https://github.com/liyimeng))
* Detect flakes in PR builder e2e runs ([#27898](https://github.com/kubernetes/kubernetes/pull/27898), [@lavalamp](https://github.com/lavalamp))

  ```

  ```
  upstreamNameservers": ["8.8.8.8", "8.8.4.4"]
  ```
  is a list of upstreamNameservers to use, overriding the configuration
  specified in `/etc/resolv.conf`.
* `kube-dns` now runs using a separate `system:serviceaccount:kube-system:kube-dns` service account which is automatically bound to the correct RBAC permissions. ([#38816](https://github.com/kubernetes/kubernetes/pull/38816), [@deads2k](https://github.com/deads2k))

tolerate zone failure.
     * Simplified way to run a container on every node (DaemonSet API (Beta) in the
Extensions API group): Kubernetes can schedule a service (such as a logging
agent) that runs one, and only one, pod per node.
     * TLS and L7 support (Ingress API (Beta) in the Extensions API group): Kubernetes
is now easier to integrate into custom networking environments by supporting

* Fix for service controller so that it won't retry on doNotRetry service update failure. ([#54184](https://github.com/kubernetes/kubernetes/pull/54184), [@MrHohn](https://github.com/MrHohn))
* [fluentd-gcp addon] Fluentd now runs in its own network, not in the host one. ([#54395](https://github.com/kubernetes/kubernetes/pull/54395), [@crassirostris](https://github.com/crassirostris))