* Check for known manifests during preflight instead of only checking for non-empty manifests directory. This makes the preflight checks less heavy-handed by specifically checking for well-known files (kube-apiserver.yaml, kube-controller-manager.yaml, kube-scheduler.yaml, etcd.yaml) in /etc/kubernetes/manifests instead of simply checking for a non-empty directory. ([#57287](https://github.com/kubernetes/kubernetes/pull/57287), [@mattkelly](https://github.com/mattkelly))

*   The Kubelet's feature gates are now specified as a map when provided via a JSON or YAML KubeletConfiguration, rather than as a string of key-value pairs, making them less awkward for users. ([#53025](https://github.com/kubernetes/k...

- Kubectl: `kubectl get` will omit managed fields by default now. Users could set `--show-managed-fields` to true to show managedFields when the output format is either `json` or `yaml`. ([#96878](https://github.com/kubernetes/kubernetes/pull/96878), [@knight42](https://github.com/knight42)) [SIG CLI and Testing]

  upgrading a cluster, all objects in resource.k8s.io/v1alpha1 (ResourceClaim, ResourceClaimTemplate,
  ResourceClass, PodScheduling) must be deleted. The changes are internal, so
  YAML files which create pods and resource claims don't need changes except for
  the newer `apiVersion`. ([#116299](https://github.com/kubernetes/kubernetes/pull/116299), [@pohly](https://github.com/pohly))

Tim Hockin <******@****.***> 1629416503 -0700

Emre Sülün <******@****.***> 1646040883 +0300

## Changelog since v1.12.0

### Other notable changes

* kubeadm now allows mixing of init/cluster and join configuration in a single YAML file (although a warning gets printed in this case).  ([#69426](https://github.com/kubernetes/kubernetes/pull/69426), [@rosti](https://github.com/rosti))

- Fix unsafe JSON construction in a number of locations in the codebase ([#81158](https://github.com/kubernetes/kubernetes/pull/81158), [@zouyee](https://github.com/zouyee))

- Kubeadm: implemented structured output of 'kubeadm config images list' command in JSON, YAML, Go template and JsonPath formats ([#86810](https://github.com/kubernetes/kubernetes/pull/86810), [@bart0sh](https://github.com/bart0sh)) [SIG Cluster Lifecycle]

	1. In Namespaces that previously had the "DefaultDeny" annotation,
	   you can create equivalent v1 semantics by creating a
	   NetworkPolicy that matches all pods but does not allow any
	   traffic:

	   ```yaml
           kind: NetworkPolicy
           apiVersion: networking.k8s.io/v1
           metadata:
             name: default-deny
           spec:
             podSelector:
	   ```