- 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]...

* Fixed cleanup of CSI metadata files. ([#65323](https://github.com/kubernetes/kubernetes/pull/65323), [@jsafrane](https://github.com/jsafrane))
* Reload systemd config files before starting kubelet. ([#65702](https://github.com/kubernetes/kubernetes/pull/65702), [@mborsz](https://github.com/mborsz))

- kubelet: the `--image-credential-provider-config` file was loaded with strict deserialization, which failed if the config file contained duplicate or unknown fields. This protected against accidentally running with malformed config files, unindented files, or typos in field names, and it prevented unexpected behavior. ([#128062](https://github.com/kubernetes/kubernetes/pull/128062), [@aramase](https://github.com/aramase)) [SIG Auth and Node]

- 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]...

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### Other notable changes

* Kubernetes json deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. ([#65157](https://github.com/kubernetes/kubernetes/pull/65157), [@caesarxuchao](https://github.com/caesarxuchao))
    * If your config files contains fields with wrong case, the config files will be now invalid.

* 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))

  specific point in time, rather than a document that may change over time.
  
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* Pre-existing log files are now opened with O_APPEND, instead of O_TRUNC. This helps prevent losing logs when components crash-loop, and also enables external log rotation utilities to truncate log files in-place without components extending log files to their pre-truncation sizes on subsequent writes. ([#74837](https://github.com/kubernetes/kubernetes/pull/74837), [@mtaufen](https:...

* 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))