* Default values differ between the Kubelet's componentconfig (config file) API and the Kubelet's command line. Be sure to review the default values when migrating to using a config file. For example, the authz mode is set to "AlwaysAllow" if you rely on the command line, but defaults to the more secure "Webhook" mode if you load config from a file. ([#59666](https://github.com/kubernetes/kubernetes/pull/59666), [@mtaufen](https://github.com/mtaufen))

for the kubelet in the dropin, a structured configuration file for the kubelet is used, and is expected to be present in `/var/lib/kubelet/config.yaml`. For runtime-detected, instance-specific configuration values, a environment file with dynamically-generated flags at `kubeadm init` or `kubeadm join` run time is used. Finally, if you want to override something specific for the kubelet that can't be done via the kubeadm Configuration file (which is preferred), you might add flags to the `KUBELET_EXTRA_ARGS`...

   * -viper-config can be used to set also the options defined by command line flags
   * the default config file is "e2e.yaml/toml/json/..." and the test starts when no such config is found (as before) but if -viper-config is used, the config file must exist
   * -viper-config can be used to select a file with full path, with or without file suffix
   * the csiImageVersion/Registry flags were renamed to storage.csi.imageVersion/Registry

 
#### Configuration file changes:

#### kube-apiserver:

* change default azure file/dir mode to 0755 ([#56551](https://github.com/kubernetes/kubernetes/pull/56551), [@andyzhangx](https://github.com/andyzhangx))
* fix incorrect error info when creating an azure file PVC failed ([#56550](https://github.com/kubernetes/kubernetes/pull/56550), [@andyzhangx](https://github.com/andyzhangx))

- Kube-log-runner: rotating log output into a new file when reaching a certain file size can be requested via the new `-log-file-size` parameter. `-log-file-age` enables automatical removal of old output files.  Periodic flushing can be requested through ` -flush-interval`. ([#127667](https://github.com/kubernetes/kubernetes/pull/127667), [@zylxjtu](h...

- kube-apiserver: The `ResourceQuota` admission plugin configuration referenced from `--admission-control-config-file` admission config has been promoted to `apiVersion: apiserver.config.k8s.io/v1`,...

  * The `--audit-policy-file` option is required if the `AdvancedAuditing` feature is not explicitly turned off (`--feature-gates=AdvancedAuditing=false`) on the API server.
  * The audit log file defaults to JSON encoding when using the advanced auditing feature gate.
  * An audit policy file without either an `apiVersion` or a `kind` field may be treated as invalid.
  * The webhook and log file now output the `v1beta1` event format.

    * `kubectl create configmap` has a new option `--from-env-file` that populates a configmap from file which follows a key=val format for each line. ([#38882](https://github.com/kubernetes/kubernetes/pull/38882), [@fraenkel](https://github.com/fraenkel))

    * `kubectl create secret` has a new option `--from-env-file` that populates a secret from file which follows a key=val format for each line.

  * Printing/describe

* kubectl commands run inside a pod using a kubeconfig file now use the namespace specified in the kubeconfig file, instead of using the pod namespace. If no kubeconfig file is used, or the kubeconfig does not specify a namespace, the pod namespace is still used as a fallback. ([#44570](https://github.com/kubernetes/kubernetes/pull/44570), [@liggitt](https://github.com/liggitt))...