## Introduction to 1.9.0

Kubernetes version 1.9 includes new features and enhancements, as well as fixes to identified issues. The release notes contain a brief overview of the important changes introduced in this release. The content is organized by Special Interest Group ([SIG](https://github.com/kubernetes/community/blob/master/sig-list.md)).

## Changelog since v1.27.5

## Changes by Kind

### API Change

- Fixed a bug where CEL expressions in CRD validation rules would incorrectly compute a high estimated cost for functions that return strings, lists or maps.

- The `controller.kubernetes.io/pod-deletion-cost` annotation can be set to offer a hint on the cost of deleting a `Pod` compared to other pods belonging to the same ReplicaSet. Pods with lower deletion cost are deleted first. This is an alpha feature. ([#99163](https://github.com/kubernetes/kubernetes/pull/99163), [@ahg-g](https://github.com/ahg-g))

* Fixed issue with charm upgrades resulting in an error state. ([#59064](https://github.com/kubernetes/kubernetes/pull/59064), [@hyperbolic2346](https://github.com/hyperbolic2346))

tabular output for API resources via a new mime-type `application/json;as=Table;v=v1alpha1;g=meta.k8s.io`.  The returned object (if the server supports it) will be of type `meta.k8s.io/v1alpha1` with `Table`, and contain column and row information related to the resource.  Each row will contain information about the resource - by default it will be the object metadata, but callers can add the `?includeObject=Object` query parameter and receive the full object.  In the future kubectl will use this to...

- github.com/docker/distribution: [v2.8.1+incompatible → v2.8.2+incompatible](https://github.com/docker/distribution/compare/v2.8.1...v2.8.2)
- github.com/dustin/go-humanize: [v1.0.0 → v1.0.1](https://github.com/dustin/go-humanize/compare/v1.0.0...v1.0.1)
- github.com/envoyproxy/go-control-plane: [49ff273 → v0.10.3](https://github.com/envoyproxy/go-control-plane/compare/49ff273...v0.10.3)

- kubeadm: remove misleading error message regarding image pulling ([#66658](https://github.com/kubernetes/kubernetes/pull/66658), [@dixudx](https://github.com/dixudx))
- kubeadm: Pull sidecar and dnsmasq-nanny images when using kube-dns ([#66499](https://github.com/kubernetes/kubernetes/pull/66499), [@rosti](https://github.com/rosti))

- Kubeadm increased to 5 minutes its timeout for the TLS bootstrapping process to complete upon join ([#89735](https://github.com/kubernetes/kubernetes/pull/89735), [@rosti](https://github.com/rosti)) [SIG Cluster Lifecycle]
- hyperkube: Use debian-hyperkube-base@v1.1.0 image
  
    A previous release built hyperkube using the debian-hyperkube-base@v1.0.0,

- Kubeadm increased to 5 minutes its timeout for the TLS bootstrapping process to complete upon join ([#89735](https://github.com/kubernetes/kubernetes/pull/89735), [@rosti](https://github.com/rosti)) [SIG Cluster Lifecycle]
- hyperkube: Use debian-hyperkube-base@v1.1.0 image
  
    A previous release built hyperkube using the debian-hyperkube-base@v1.0.0,

- kubeadm: Multiple API server endpoints support upon join is removed as it is now redundant. ([#69812](https://github.com/kubernetes/kubernetes/pull/69812), [@rosti](https://github.com/rosti))