cluster.ninja

Kubernetes minor release · “The Next Frontier”

Kubernetes 1.23

The final release of 2021 made dual-stack networking and the autoscaling/v2 HPA API GA, moved PodSecurity admission to beta with the gate on, defaulted to CRI v1, and deprecated FlexVolume.

End of life

End of life since 28 Feb 2023 (3.7 years ago). No more patches upstream.

Released7 Dec 2021
Maintenance mode—
End of life28 Feb 2023
Latest patch1.23.1728 Feb 2023
Patch releases17
Support span14.7 months

What 1.23 brought

GA

Dual-stack networking GA

IPv4/IPv6 dual-stack is GA and its feature gate is removed. Pods and Services still default to single-stack unless configured otherwise.

GA

HPA autoscaling/v2 is GA

The HorizontalPodAutoscaler autoscaling/v2 API is stable, and autoscaling/v2beta2 is now deprecated.

beta

PodSecurity admission

The PodSecurity admission controller, which applies Pod Security Standards per namespace via labels, is beta and enabled by default.

change

CRI v1 becomes the default

The kubelet uses the CRI v1 API by default, falling back to v1alpha2 for runtimes without v1; no user action is needed.

GA

Generic ephemeral volumes GA

Pod-scoped volumes from any dynamically provisioning driver are GA, along with skipping recursive ownership changes for faster pod startup.

beta

CSI migration progress

CSI migration is on by default but still beta for GCE PD, AWS EBS and Azure Disk; Ceph RBD and Portworx migration arrive as alpha.

Summarised in our own words from the official “Kubernetes 1.23: The Next Frontier” announcement (47 tracked enhancements), © The Kubernetes Authors, CC BY 4.0.

APIs that stopped being served in 1.23

No API versions were removed in 1.23.

Other removals and deprecations

Removed

  • The IPv6DualStack feature gate is removed now that dual-stack networking is GA.

Deprecated

  • FlexVolume is deprecated; driver maintainers and users should move to out-of-tree CSI drivers.
  • Several klog-specific logging flags are deprecated and their implementation will be removed in a later release.
  • The HorizontalPodAutoscaler autoscaling/v2beta2 API is deprecated in favour of autoscaling/v2.

From the release announcement; our wording.

API versions deprecated in 1.23

Still served in 1.23, but the API server answers with a deprecation warning and a removal is scheduled.

KindAPI versionStops being servedUse instead
FlowSchema flowcontrol.apiserver.k8s.io/v1beta1 1.26 flowcontrol.apiserver.k8s.io/v1
PriorityLevelConfiguration flowcontrol.apiserver.k8s.io/v1beta1 1.26 flowcontrol.apiserver.k8s.io/v1

Stable (GA) API kinds new in 1.23

HorizontalPodAutoscaler autoscaling/v2

Upgrading

Version skew with a 1.23 API server

  • kubelet, kube-proxy: 1.21 to 1.23
  • kube-controller-manager, scheduler: 1.22 to 1.23
  • kubectl: 1.22 to 1.24

From the official version skew policy as it stands today.

One minor at a time

The API server must not skip minor versions.

Patch releases

18 releases, newest first
  1. 1.23.1728 Feb 2023
  2. 1.23.1618 Jan 2023
  3. 1.23.158 Dec 2022
  4. 1.23.1410 Nov 2022
  5. 1.23.1313 Oct 2022
  6. 1.23.1221 Sep 2022
  7. 1.23.1115 Sep 2022
  8. 1.23.1017 Aug 2022
  9. 1.23.913 Jul 2022
  10. 1.23.816 Jun 2022
  11. 1.23.725 May 2022
  12. 1.23.620 Apr 2022
  13. 1.23.516 Mar 2022
  14. 1.23.417 Feb 2022
  15. 1.23.326 Jan 2022
  16. 1.23.219 Jan 2022
  17. 1.23.116 Dec 2021
  18. 1.23.07 Dec 2021