- `apidiscovery.k8s.io/v2beta1` API group is disabled by default ([#130347](https://github.com/kubernetes/kubernetes/pull/130347), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery and Testing]
- `kubectl apply` now coerces `null` values for labels and annotations in manifests to empty string values, 

  - 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

* 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

- Update the Event series starting count when emitting isomorphic events from 1 to 2. ([#119375](https://github.com/kubernetes/kubernetes/pull/119375), [@dgrisonnet](https://github.com/dgrisonnet)) [SIG API Machinery and Testing]

## Dependencies

  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))

- Ubuntu 18.04 (Bionic) series has been added to Juju charms ([#65644](https://github.com/kubernetes/kubernetes/pull/65644), [@tvansteenburgh](https://github.com/tvansteenburgh))

- '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

* kube-apiserver now serves OpenAPI specs for registered CRDs with defined  ([#71192](https://github.com/kubernetes/kubernetes/pull/71192), [@roycaihw](https://github.com/roycaihw))

* Fixes an issue with kubelet-reported pod status on deleted/recreated pods. ([#86320](https://github.com/kubernetes/kubernetes/pull/86320), [@liggitt](https://github.com/liggitt))
* kube-apiserver no longer serves the following deprecated APIs: ([#85903](https://github.com/kubernetes/kubernetes/pull/85903), [@liggitt](https://github.com/liggitt))
  * All resources under `apps/v1beta1` and `apps/v1beta2` - use `apps/v1` instead

- The ingress `v1beta1` has been deprecated. ([#102030](https://github.com/kubernetes/kubernetes/pull/102030), [@aojea](https://github.com/aojea))

### API Change