* When HPAScaleToZero feature gate is enabled HPA supports scaling to zero pods based on object or external metrics. HPA remains active as long as at least one metric value available. ([#74526](https://github.com/kubernetes/kubernetes/pull/74526), [@DXist](https://github.com/DXist))
    * To downgrade the cluster to version that does not support scale-to-zero feature:

- Added a kubelet socket which serves an grpc service containing the devices used by containers on the node. ([#70508](https://github.com/kubernetes/kubernetes/pull/70508), [@dashpole](https://github.com/dashpole))

- Added an e2e test to verify that the cluster is not vulnerable to CVE-2021-29923 when using Services with IPs with leading zeros, note that this test is a necessary but not sufficient condition, all the components in the clusters that consume IPs addresses from the APIs MUST interpret them as decimal or discard them. ([#107552](https://github.com/kubernetes/kubernetes/pull/107552),...

  * Writes the federation kubeconfig to the local kubeconfig file.
* Update the series and the README to reflect the change. ([#30374](https://github.com/kubernetes/kubernetes/pull/30374), [@mbruzek](https://github.com/mbruzek))

     * ensure that completed write operations performed by other threads are noticed. For most
     * purposes, the "count" field, tracking the number of elements, serves as that volatile
     * variable ensuring visibility. This is convenient because this field needs to be read in many
     * read operations anyway:
     *

  the garbage collector starts to manage it.


#### Monitoring/Prometheus
* [action required] The WATCHLIST calls are now reported as WATCH verbs in prometheus for the apiserver_request_* series.  A new "scope" label is added to all apiserver_request_* values that is either 'cluster', 'resource', or 'namespace' depending on which level the query is performed at.([#52237](https://github.com/kubernetes/kubernetes/pull/52237))

health.vn healthcare heavy.jp heguri.nara.jp heimatunduhren.museum hekinan.aichi.jp hellas.museum help helsinki helsinki.museum hembygdsforbund.museum hemne.no hemnes.no hemsedal.no hepforge.org her.jp herad.no here here-for-more.info heritage.museum hermes herokuapp.com herokussl.com heroy.more-og-romsdal.no heroy.nordland.no herøy.møre-og-romsdal.no herøy.nordland.no heteml.net hgtv hi.cn hi.us hicam.net hichiso.gifu.jp hida.gifu.jp hidaka.hokkaido.jp hidaka.kochi.jp hidaka.saitama.jp hidaka.wakayama.jp...

  - The `export` query parameter for list API calls, deprecated since v1.14, will be removed in v1.18.
  - The `series.state` field in the events.k8s.io/v1beta1 Event API is deprecated and will be removed in v1.18 ([#75987](https://github.com/kubernetes/kubernetes/pull/75987), [@yastij](https://github.com/yastij))

- kubeadm

- 'kubeadm: marked the flag "--experimental-output'' as deprecated (it will
  be removed in a future release) and added a new flag ''--output" that serves the
  same purpose. Affected commands are - "kubeadm config images list", "kubeadm token

* Splits Juju Charm layers into master/worker roles ([#40324](https://github.com/kubernetes/kubernetes/pull/40324), [@chuckbutler](https://github.com/chuckbutler))
    * Adds support for 1.5.x series of Kubernetes
    * Introduces a tactic for keeping templates in sync with upstream eliminating template drift
    * Adds CNI support to the Juju Charms
    * Adds durable storage support to the Juju Charms