### **Cluster Lifecycle**

*   You must either specify the `--discovery-token-ca-cert-hash` flag to `kubeadm join`, or opt out of the CA pinning feature using `--discovery-token-unsafe-skip-ca-verification`.
*   The default `auto-detect` behavior of the kubelet's `--cloud-provider` flag is removed.

* The kube-apiserver discovery APIs (for example, `/apis`) return information about the API groups being served, and can change dynamically.
During server startup, prior to the server reporting healthy (via `/healthz`), not all API groups may be reported.
Wait for the server to report healthy (via `/healthz`) before depending on the information provided by the discovery APIs.

### API Server Aggregator
* Rename kubernetes-discovery to kube-aggregator ([#39619](https://github.com/kubernetes/kubernetes/pull/39619), [@deads2k](https://github.com/deads2k))
* Fix connection upgrades through kubernetes-discovery ([#38724](https://github.com/kubernetes/kubernetes/pull/38724), [@deads2k](https://github.com/deads2k))

#### Generic API Server

- Fixed cluster autoscaler addon permissions so it can access batch/job. ([#69858](https://github.com/kubernetes/kubernetes/pull/69858), [@losipiuk](https://github.com/losipiuk))

- Added an example for kubectl delete with the --interactive flag. ([#127512](https://github.com/kubernetes/kubernetes/pull/127512), [@bergerhoffer](https://github.com/bergerhoffer)) [SIG CLI]
- Aggregated Discovery v2beta1 fixture is removed in `./api/discovery`. Please use v2 ([#127008](https://github.com/kubernetes/kubernetes/pull/127008), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery]

* Pass-through volume MountOptions to global mount (NodeStageVolume) on the node for CSI ([#80191](https://github.com/kubernetes/kubernetes/pull/80191), [@davidz627](https://github.com/davidz627))
* 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))

* FC volume plugin: Support WWID for volume identifier ([#48741](https://github.com/kubernetes/kubernetes/pull/48741), [@mtanino](https://github.com/mtanino))
* kubeadm: added enhanced TLS validation for token-based discovery in `kubeadm join` using a new `--discovery-token-ca-cert-hash` flag. ([#49520](https://github.com/kubernetes/kubernetes/pull/49520), [@mattmoyer](https://github.com/mattmoyer))

- Kubeadm: fixed a regression where the JoinConfiguration.discovery.timeout was no longer respected and the value was always hardcoded to "5m" (5 minutes). ([#125481](https://github.com/kubernetes/kubernetes/pull/125481), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

	}

	// Configure an OpenID Connect aware OAuth2 client.
	oauth2Config := oauth2.Config{
		ClientID:     pro.ClientID,
		ClientSecret: pro.ClientSecret,
		RedirectURL:  pro.RedirectURL,

		// Discovery returns the OAuth2 endpoints.
		Endpoint: provider.Endpoint(),

		// "openid" is a required scope for OpenID Connect flows.
		Scopes: []string{oidc.ScopeOpenID, "groups"},
	}

* attachdetach controller attaches volumes immediately when Pod's PVCs are bound ([#66863](https://github.com/kubernetes/kubernetes/pull/66863), [@cofyc](https://github.com/cofyc))
* kube-apiserver now includes all registered API groups in discovery, including registered extension API group/versions for unavailable extension API servers. ([#66932](https://github.com/kubernetes/kubernetes/pull/66932), [@nilebox](https://github.com/nilebox))