### Instrumentation

In v1.9 we focused on improving stability of the components owned by the SIG, including Heapster, Custom Metrics API adapters for Prometheus, and Stackdriver.

now always set to "systemd" unless the user is explicit about it. This requires existing machine setups to configure the container runtime to use the "systemd" driver. Documentation on this topic can be found here: https://kubernetes.io/docs/setup/production-environment/container-runtimes/. When upgrading existing clusters / nodes using "kubeadm upgrade" the old cgroupDriver value is preserved, but in 1.22 this change will also apply to "upgrade". For more information on migrating to the "systemd" driver...

## Changelog since v1.10.5

### Action Required

* ACTION REQUIRED: Removes defaulting of CSI file system type to ext4. All the production drivers listed under https://kubernetes-csi.github.io/docs/drivers.html were inspected and should not be impacted after this change. If you are using a driver not in that list, please test the drivers on an updated test cluster first. ([#65499]...

[SIG Cluster Lifecycle]: https://github.com/kubernetes/community/tree/master/sig-cluster-lifecycle

### SIG Instrumentation

[SIG Instrumentation][] is responsible for metrics production and
collection.

For the 1.8 release, SIG Instrumentation focused on stabilizing the APIs
and components that are required to support the new version of the Horizontal Pod

## Changelog since v1.11.0

### Action Required

CSI was first introduction as alpha in Kubernetes v1.9 and moved to beta in Kubernetes v1.10.

You can find a list of sample and production drivers in the [CSI Documentation](https://kubernetes.io/docs/concepts/storage/volumes/#csi).

    - [Ingress graduates to General Availability](#ingress-graduates-to-general-availability)
    - [seccomp graduates to General Availability](#seccomp-graduates-to-general-availability)
    - [Production images moved to community control](#production-images-moved-to-community-control)
    - [KubeSchedulerConfiguration graduates to Beta](#kubeschedulerconfiguration-graduates-to-beta)

* libvirt-coreos: Download the coreos_production_qemu_image over SSL. ([#34646](https://github.com/kubernetes/kubernetes/pull/34646), [@roberthbailey](https://github.com/roberthbailey))

- kube-apiserver

  - the `--basic-auth-file` flag and authentication mode is deprecated and will be removed in a future release. It is not recommended for production environments. ([#81152](https://github.com/kubernetes/kubernetes/pull/81152), [@tedyu](https://github.com/tedyu))