* Bug fixes:

  * Fix serialization of EnforceNodeAllocatable ([#44606](https://github.com/kubernetes/kubernetes/pull/44606), [@ivan4th](https://github.com/ivan4th))

	* Use OS-specific libs when computing client User-Agent in kubectl, etc. ([#44423](https://github.com/kubernetes/kubernetes/pull/44423), [@monopole](https://github.com/monopole))


#### Instrumentation

- kubeadm: run kernel version and OS version preflight checks for `kubeadm upgrade`. ([#129401](https://github.com/kubernetes/kubernetes/pull/129401), [@pacoxu](https://github.com/pacoxu))

*   1.  Install tf-keras via pip install tf-keras~=2.16

    1.  To switch tf.keras to use Keras 2 (tf-keras), set the environment
        variable TF_USE_LEGACY_KERAS=1 directly or in your python program by
        import os;os.environ["TF_USE_LEGACY_KERAS"]=1. Please note that this
        will set it for all packages in your Python runtime program

*   1.  Change import of keras from tensorflow as follows

</p>

<pre class="grammar">
"var" IdentifierList "=" ExpressionList .
</pre>

<pre>
i, j := 0, 10
f := func() int { return 7 }
ch := make(chan int)
r, w, _ := os.Pipe()  // os.Pipe() returns a connected pair of Files and an error, if any
_, y, _ := coord(p)   // coord() returns three values; only interested in y coordinate
</pre>

<p>

    </magic>
    <glob pattern="*.exr"/>
  </mime-type>

  <mime-type type="image/x-os2-graphics; charset=binary">
    <_comment>OS2 bitmap array</_comment>
    <tika:link>http://fileformats.archiveteam.org/wiki/OS/2_Bitmap_Array</tika:link>
    <magic priority="50">
      <match value="BA" type="string" offset="0">
        <match value="BM" type="string" offset="14"/>
        <match value="CI" type="string" offset="14"/>

* kubeadm: Adds dry-run support for kubeadm using the `--dry-run` option ([#50631](https://github.com/kubernetes/kubernetes/pull/50631), [@luxas](https://github.com/luxas))
* Change GCE installs (kube-up.sh) to use GCI/COS for node OS, by default. ([#46512](https://github.com/kubernetes/kubernetes/pull/46512), [@thockin](https://github.com/thockin))

    *  - User should be able to create k8s cluster which spans across multiple ESXi clusters, datacenters or even vCenters.
    *  - vSphere cloud provider (VCP) uses OS hostname and not vSphere Inventory VM Name.
    *    That means, now  VCP can handle cases where user changes VM inventory name.
    * - VCP can handle cases where VM migrates to other ESXi cluster or datacenter or vCenter.

* 👷 Add pre-commit GitHub Action workflow. PR [#4895](https://github.com/tiangolo/fastapi/pull/4895) by [@tiangolo](https://github.com/tiangolo).
* 📝 Add dark mode auto switch to docs based on OS preference. PR [#4869](https://github.com/tiangolo/fastapi/pull/4869) by [@ComicShrimp](https://github.com/ComicShrimp).

- kubelet

  - the `--containerized` flag was deprecated in 1.14 and has been removed ([#80043](https://github.com/kubernetes/kubernetes/pull/80043), [@dims](https://github.com/dims))
  - the `beta.kubernetes.io/os` and `beta.kubernetes.io/arch` labels, deprecated since v1.14, are targeted for removal in v1.18.

pkg net, method (IP) MarshalText() ([]uint8, error)
pkg net, type Dialer struct, DualStack bool
pkg net/smtp, method (*Client) Close() error
pkg os (linux-arm), const O_SYNC = 1052672
pkg os (linux-arm-cgo), const O_SYNC = 1052672
pkg reflect, method (Value) SetCap(int)
pkg reflect, method (Value) Slice3(int, int, int) Value
pkg runtime, type MemStats struct, GCSys uint64