- Some kubeadm commands are now allowed to work in a completely offline mode.
- Certificate handling improvements:
  - Renew certs as part of upgrade.
  - New `kubeadm alpha phase certs renew` command for renewing certificates.
  - Certificates created with kubeadm now have improved uniqueness of Distinguished Name fields.
- HA improvements:

    - [Added metrics](#added-metrics)
    - [Deprecated/changed metrics](#deprecatedchanged-metrics)
  - [Notable Features](#notable-features)
    - [Stable](#stable)
    - [Beta](#beta)
    - [CLI Improvements](#cli-improvements)
  - [API Changes](#api-changes)
  - [Other notable changes](#other-notable-changes-1)
    - [API Machinery](#api-machinery)
    - [Apps](#apps)
    - [Auth](#auth)
    - [CLI](#cli)

For the 1.8 release, SIG Node continued to focus
on a broad set of workload types, including hardware and performance
sensitive workloads such as data analytics and deep learning. The SIG also
delivered incremental improvements to node reliability.

[SIG Node]: https://github.com/kubernetes/community/tree/master/sig-node

### SIG Network

[SIG Network][] is responsible for networking components, APIs, and plugins in Kubernetes.

- 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/kub...

* Metadata Agent Improvements ([#66485](https://github.com/kubernetes/kubernetes/pull/66485), [@bmoyles0117](https://github.com/bmoyles0117))
    * Bump metadata agent version to 0.2-0.0.21-1.
    * Expand the metadata agent's access to all API groups.

### Auth

- Performance improvements in `klog` ([#115277](https://github.com/kubernetes/kubernetes/pull/115277), [@pohly](https://github.com/pohly))

    - [CustomResourceDefinition OpenAPI Publishing](#customresourcedefinition-openapi-publishing)
  - [Cluster Lifecycle Stability and Usability Improvements](#cluster-lifecycle-stability-and-usability-improvements)
  - [Continued improvement of CSI](#continued-improvement-of-csi)
    - [Additional Notable Feature Updates](#additional-notable-feature-updates)
  - [Known Issues](#known-issues)

In this release the SIG again focused on further improving the user experience on cluster creation and also fixing a number of bugs and other assorted improvements.

Some notable changes in kubeadm since Kubernetes 1.12:

    * action required: users deploying workloads with priority lower than 0 may want to use priority lower than -10 to avoid triggering scale-up.

### Other notable changes

* Metadata Agent Improvements ([#66485](https://github.com/kubernetes/kubernetes/pull/66485), [@bmoyles0117](https://github.com/bmoyles0117))
    * Bump metadata agent version to 0.2-0.0.21-1.
    * Expand the metadata agent's access to all API groups.