### Documentation

- `kubectl debug` will now print a warning message when using the `--target` option since many container runtimes do not support this yet. ([#101074](https://github.com/kubernetes/kubernetes/pull/101074), [@verb](https://github.com/verb)) [SIG CLI]

### Bug or Regression

  you want to set the equivalent of any of the `--iptables-xxx` options.)
  
  As this code is still very new, it has not been heavily optimized yet;
  while it is expected to _eventually_ have better performance than the
  iptables backend, very little performance testing has been done so far. ([#121046](https://github.com/kubernetes/kubernetes/pull/121046), [@danwinship](https://github.com/danwinship))

- `kubectl debug` gains support for changing container images when copying a pod for debugging, similar to how `kubectl set image` works. See `kubectl help debug` for more information. ([#96058](https://github.com/kubernetes/kubernetes/pull/96058), [@verb](https://github.com/verb)) [SIG CLI]

### Documentation

- Fix handling tombstones in pod-disruption-budged controller. ([#83951](https://github.com/kubernetes/kubernetes/pull/83951), [@zouyee](https://github.com/zouyee))

- The underlying format of the `CPUManager` state file has changed. Upgrades should be seamless, but any third-party tools that rely on reading the previous format need to be updated. ([#84462](https://github.com/kub...

    - [SIG VMWare](#sig-vmware-1)
    - [SIG Windows](#sig-windows-1)
  - [Other Notable Changes](#other-notable-changes-11)
    - [Bug Fixes](#bug-fixes)
    - [Not Very Notable (that is, non-user-facing)](#not-very-notable-that-is-non-user-facing)
  - [External Dependencies](#external-dependencies)
- [v1.12.0-rc.2](#v1120-rc2)
  - [Downloads for v1.12.0-rc.2](#downloads-for-v1120-rc2)

- Static pods were taking extra time to be restarted after being updated.  Static pods that are waiting to restart were not correctly counted in `kubelet_working_pods`. ([#116995](https://github.com/kubernetes/kubernetes/pull/116995), [@smarterclayton](https://github.com/smarterclayton)) [SIG Node]

processes in other containers in a pod, but it also means that the `kubectl exec {pod} kill 1` pattern will cause the Pod to be restarted rather than a single container. ([#45236](https://github.com/kubernetes/kubernetes/pull/45236), [@verb](https://github.com/verb))

  * A new field hostAliases has been added to the pod spec to support [adding entries to a Pod's /etc/hosts file](https://kubernetes.io/docs/concepts/services-networking/add-entries-to-pod-etc-hosts-with-host-aliases/). ...

* The following deprecated flags were removed from `kube-controller-manager`:

  * `replication-controller-lookup-cache-size`
  * `replicaset-lookup-cache-size`
  * `daemonset-lookup-cache-size`

  Don't use these flags. Using deprecated flags causes the server to print a warning. Using a removed flag causes the server to abort the startup.

* The following deprecated flags were removed from `kubelet`:

  managed by the GLBC Ingress Controller. This can cause the health checks to start failing,
  requiring you to reapply the manual edits.
  * This issue does not affect clusters that were already running Kubernetes v1.6.4 or higher.
  * This issue does not affect Health Checks that were left in the configuration
    [originally set by the GLBC Ingress Controller](https://github.com/kubernetes/ingress-nginx/tree/0.9.0-beta.1/controllers/gce#health-checks).