upgrading, and deleting clusters.

For the 1.8 release, SIG Cluster Lifecycle continued to focus on expanding the
capabilities of kubeadm, which is both a user-facing tool to manage clusters
and a building block for higher-level provisioning systems. Starting
with the 1.8 release, kubeadm supports a new upgrade command and includes alpha
support for self hosting the cluster control plane.

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))
* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

* DaemonSets [can now be updated by a rolling update](https://kubernetes.io/docs/tasks/manage-daemon/update-daemon-set).

## Action Required

### Certificates API

### CSIDriver policy for FSGroup graduates to Beta

The FSGroup's CSIDriver Policy is now beta in 1.20. This allows CSIDrivers to explicitly indicate if they want Kubernetes to manage permissions and ownership for their volumes via `fsgroup`. 

### Security Improvements for CSI Drivers (Alpha)

   ([#122830](https://github.com/kubernetes/kubernetes/pull/122830), [@p0lyn0mial](https://github.com/p0lyn0mial))
- Updated `ImageGCMaxAge` behavior in the kubelet to wait the `MaxAge` duration after the kubelet has restarted before garbage collecting.
   ([#123343](https://github.com/kubernetes/kubernetes/pull/123343), [@haircommander](https://github.com/haircommander))

#### DaemonSet
* [beta] DaemonSet supports history and rollback. See [Performing a Rollback on a DaemonSet](https://kubernetes.io/docs/tasks/manage-daemon/rollback-daemon-set/).

#### Deployments

- Graduated the `MultiCIDRServiceAllocator` feature gate to stable, and the `DisableAllocatorDualWrite` feature gate to beta (disabled by default).
**Action required** for Kubernetes cluster administrators and for distributions that manage the cluster Service CIDR.
Kubernetes now allows users to define the cluster Service CIDR via an API object: ServiceCIDR.

- Updated the control plane's trust anchor publisher to create and manage a new ClusterTrustBundle object, associated with the `kubernetes.io/kube-apiserver-serving` X.509 certificate signer. This ClusterTrustBundle contains a PEM bundle in its payload that you can use to verify kube-apiserver serving certificates. ([#...

* Fixed API server panic during concurrent GET or LIST requests with non-empty `resourceVersion`. ([#65092](https://github.com/kubernetes/kubernetes/pull/65092), [@sttts](https://github.com/sttts))
* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

Besides the above new features, support for Azure Virtual Machine Scale Sets (VMSS) and Cluster-Autoscaler is now stable and considered GA:

- Azure virtual machine scale sets (VMSS) allow you to create and manage identical load balanced VMs that automatically increase or decrease based on demand or a set schedule.