<p>
The syntax is specified using a
<a href="https://en.wikipedia.org/wiki/Wirth_syntax_notation">variant</a>
of Extended Backus-Naur Form (EBNF):
</p>

<pre class="grammar">
Syntax      = { Production } .
Production  = production_name "=" [ Expression ] "." .
Expression  = Term { "|" Term } .
Term        = Factor { Factor } .
Factor      = production_name | token [ "…" token ] | Group | Option | Repetition .

* ACTION REQUIRED: Removes defaulting of CSI file system type to ext4. All the production drivers listed under https://kubernetes-csi.github.io/docs/drivers.html were inspected and should not be impacted after this change. If you are using a driver not in that list, please test the drivers on an updated test cluster first. ([#65499]...

now always set to "systemd" unless the user is explicit about it. This requires existing machine setups to configure the container runtime to use the "systemd" driver. Documentation on this topic can be found here: https://kubernetes.io/docs/setup/production-environment/container-runtimes/. When upgrading existing clusters / nodes using "kubeadm upgrade" the old cgroupDriver value is preserved, but in 1.22 this change will also apply to "upgrade". For more information on migrating to the "systemd" driver...

  purposes, you can use older kernels, as far back as 5.4, if you set the
  `nftables.skipKernelVersionCheck` option in the kube-proxy config, but this is not
  recommended in production since it may cause problems with other nftables
  users on the system.) ([#124152](https://github.com/kubernetes/kubernetes/pull/124152), [@danwinship](https://github.com/danwinship)) [SIG Network]

 *   Added utility `tf.keras.utils.FeatureSpace`, a one-stop shop for structured data preprocessing and encoding.

## **Major Themes**

Kubernetes 1.7 is a milestone release that adds security, stateful application, and extensibility features motivated by widespread production use of Kubernetes.

[SIG Cluster Lifecycle]: https://github.com/kubernetes/community/tree/master/sig-cluster-lifecycle

### SIG Instrumentation

[SIG Instrumentation][] is responsible for metrics production and
collection.

For the 1.8 release, SIG Instrumentation focused on stabilizing the APIs
and components that are required to support the new version of the Horizontal Pod

### Etcd v3.5.[0-2] data corruption

Data corruption issue was found in etcd v3.5.0 release that was shipped with 1.22 Kubernetes release. Please read up-to-date [production recommendations for etcd](https://github.com/etcd-io/etcd/tree/main/CHANGELOG).

## Urgent Upgrade Notes 

### (No, really, you MUST read this before you upgrade)