- If `kubeadm reset` finds no etcd member ID for the peer it removes during the `remove-etcd-member` phase, it continues immediately to other phases, instead of retrying the phase for up to 3 minutes before continuing. ([#117948](https://github.com/kubernetes/kubernetes/pull/117948), [@dlipovetsky](https://github.com/dlipovetsky))...

* Add automatic etcd 3.2->3.1 and 3.1->3.0 minor version rollback support to gcr.io/google_container/etcd images. For HA clusters, all members must be stopped before performing a rollback. ([#59298](https://github.com/kubernetes/kubernetes/pull/59298), [@jpbetz](https://github.com/jpbetz))

- Kubeadm: fix a bug where "kubeadm join" would not properly handle missing names for existing etcd members. ([#97372](https://github.com/kubernetes/kubernetes/pull/97372), [@ihgann](https://github.com/ihgann)) [SIG Cluster Lifecycle]

* Add automatic etcd 3.2->3.1 and 3.1->3.0 minor version rollback support to gcr.io/google_container/etcd images. For HA clusters, all members must be stopped before performing a rollback. ([#59298](https://github.com/kubernetes/kubernetes/pull/59298), [@jpbetz](https://github.com/jpbetz))

- Kubeadm: apply further improvements to the tentative support for concurrent etcd member join. Fixes a bug where multiple members can receive the same hostname. Increase the etcd client dial timeout and retry timeout for add/remove/... operations. ([#87505](https://github.com/kubernetes/kubernetes/pull/87505), [@neolit123](https://github.com/neolit123)) [SIG...

- If `kubeadm reset` finds no etcd member ID for the peer it removes during the `remove-etcd-member` phase, it continues immediately to other phases, instead of retrying the phase for up to 3 minutes before continuing. ([#117724](https://github.com/kubernetes/kubernetes/pull/117724), [@dlipovetsky](https://github.com/dlipovetsky))...

[Setup topics]: https://kubernetes.io/docs/setup/pick-right-solution/
[SIGs]: https://github.com/kubernetes/community/blob/master/sig-list.md


## Major Themes

Kubernetes is developed by community members whose work is organized into
[Special Interest Groups][]. For the 1.8 release, each SIG provides the
themes that guided their work.

- Kubeadm init phase certs now support the `--csr-only` option, simplifying custom CA creation.
- `kubeadm join --experimental-control-plane` now automatically adds a new etcd member for `local etcd` mode, further simplifying required tasks for HA clusters setup.
- Improvements were made to `kubeadm reset` related to cleaning  etcd and notifying the user about the state of iptables.

- Kubeadm: modify the etcd static Pod liveness and readyness probes to use a new etcd 3.5.3+ HTTP(s) health check endpoint "/health?serializable=true" that allows to track the health of individual etcd members and not fail all members if a single member is not healthy in the etcd cluster. ([#110072](https://github.com/kubernetes/kubernetes/pull/110072), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- Kubeadm: during "join", don't re-add an etcd member if it already exists in the cluster. ([#92118](https://github.com/kubernetes/kubernetes/pull/92118), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]