* Check if container memory stats are available before accessing it ([#77656](https://github.com/kubernetes/kubernetes/pull/77656), [@yastij](https://github.com/yastij))
* client-go and kubectl no longer write cached discovery files with world-accessible file permissions ([#77874](https://github.com/kubernetes/kubernetes/pull/77874), [@yuchengwu](https://github.com/yuchengwu))

- Kubeadm: warn but do not error out on missing "ca.key" files for root CA, front-proxy CA and etcd CA, during "kubeadm join --control-plane" if the user has provided all certificates, keys and kubeconfig files which require signing with the given CA keys. ([#94988](https://github.com/kubernetes/kubernetes/pull/94988), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]...

## Changelog since v1.8.14

### Action Required

* ACTION REQUIRED: Kubernetes JSON deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. If your config files contains fields with wrong case, the config files will be now invalid. ([#65410](https://github.com/kubernetes/kubernetes/pull/65410), [@nikhita](https://github.com/nikhita))

### Other notable changes

- Kubeadm now warns (instead of error out) on missing "ca.key" files for root CA, front-proxy CA and etcd CA, during "kubeadm join --control-plane" if the user has provided all certificates, keys and kubeconfig files which require signing with the given CA keys. ([#94988](https://github.com/kubernetes/kubernetes/pull/94988), [@neolit123](https://github.com/neolit123))

- Fix remove the etcd member from the cluster during a kubeadm reset. ([#79326](https://github.com/kubernetes/kubernetes/pull/79326), [@bradbeam](https://github.com/bradbeam))

  specific point in time, rather than a document that may change over time.
  
  See here for guidance on getting permanent links to files: https://help.github.com/en/articles/getting-permanent-links-to-files
  
  Please use the following format for linking documentation:
  - [KEP]: <link>
  - [Usage]: <link>
  - [Other doc]: <link>

* Fix error in `kubeadm join --discovery-file` when using discovery files with embedded credentials ([#80675](https://github.com/kubernetes/kubernetes/pull/80675), [@fabriziopandini](https://github.com/fabriziopandini))

  specific point in time, rather than a document that may change over time.
  
  See here for guidance on getting permanent links to files: https://help.github.com/en/articles/getting-permanent-links-to-files
  
  Please use the following format for linking documentation:
  - [KEP]: <link>
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  - [Other doc]: <link>

</p>

<p>
The declaration order of variables declared in multiple files is determined
by the order in which the files are presented to the compiler: Variables
declared in the first file are declared before any of the variables declared
in the second file, and so on.
To ensure reproducible initialization behavior, build systems are encouraged
to present multiple files belonging to the same package in lexical file name
order to a compiler.

* Restored the ability of kubectl running inside a pod to consume resource files specifying a different namespace than the one the pod is running in. ([#44862](https://github.com/kubernetes/kubernetes/pull/44862), [@liggitt](https://github.com/liggitt))