* Filter published OpenAPI schema by making nullable, required fields non-required in order to avoid kubectl to wrongly reject null values. ([#85722](https://github.com/kubernetes/kubernetes/pull/85722), [@sttts](https://github.com/sttts))

* Move HighWaterMark to the top of the struct in order to fix arm ([#33117](https://github.com/kubernetes/kubernetes/pull/33117), [@luxas](https://github.com/luxas))
* Move HighWaterMark to the top of the struct in order to fix arm, second time ([#33376](https://github.com/kubernetes/kubernetes/pull/33376), [@luxas](https://github.com/luxas))



# v1.4.0

Please see the [Releases Page](https://github.com/kubernetes/kubernetes/releases) for older releases.

Release notes of older releases can be found in:
- [CHANGELOG-1.2.md](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.2.md)

Please see the [Releases Page](https://github.com/kubernetes/kubernetes/releases) for older releases.

Release notes of older releases can be found in:
- [CHANGELOG-1.2.md](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.2.md)

- `kubeadm`: will now allow deploying a kubelet that is 3 versions older than the version of `kubeadm` (N-3). This aligns with the recent change made by SIG Architecture that extends the support skew between the control plane and kubelets. Tolerate this new kubelet skew for the commands `init`, `join` and `upgrade`. Note that if the `kubeadm` user applies a control plane version that is older than the `kubeadm` version (N-1 maximum) then the skew between the kubelet and control...

- Enabled mTLS encryption between etcd and kube-apiserver in GCE ([#70144](https://github.com/kubernetes/kubernetes/pull/70144), [@wenjiaswe](https://github.com/wenjiaswe))
- Added `ResourceVersion` as a precondition for delete in order to ensure a delete fails if an unobserved change happens to an object. ([#74040](https://github.com/kubernetes/kubernetes/pull/74040), [@ajatprabha](https://github.com/ajatprabha))

### Action required

  * Docker v1.9.1 is officially recommended. Docker v1.8.3 and Docker v1.10 are
supported. If you are using an older release of Docker, please upgrade. Known
issues with Docker 1.9.1 can be found below.
  * CPU hardcapping will be enabled by default for containers with CPU limit set,

- `DynamicKubeletConfig` feature gate has been removed from the API server.
  Dynamic kubelet reconfiguration now can't be used even when older nodes are still
  attempting to rely on it. This is aligned with the Kubernetes version skew policy.
   ([#112643](https://github.com/kubernetes/kubernetes/pull/112643), [@SergeyKanzhelev](https://github.com/SergeyKanzhelev))