The Kubernetes 1.23 release was shipped on December 7. It’s the final release of 2021.
There are a ton of improvements in 1.23. You get more details from the official blog post and the changelog. Also, Víctor Jiménez Cerrada and the team at Sysdig have put together another comprehensive blog post about what’s changing, which I highly recommend. But here are a few highlights.
The Ephemeral containers feature moves from alpha to beta, which means it’s enabled by default in 1.23 clusters. Ephemeral containers are an excellent tool for troubleshooting, and we’ve written a hands-on guide to using them.
In this release IPv4/IPv6 dual-stack networking support graduates to stable. If you’ve been following the saga of adding IPv6 support to Kubernetes, it’s been a long road. Users ran into problems with the initial implementation, but it’s finally ready for prime time now. It’s exciting to see. Kudos to the team for working with the community on this. It’s very important.
PodSecurity also moves to beta. It’s the replacement for PodSecurity Policies. The official blog post describes it as “an admission controller that enforces Pod Security Standards on Pods in a Namespace based on specific namespace labels that set the enforcement level.” It’s been great to see the security tools built into Kubernetes advancing. This is a feature to have a look at for sure.
If you’ve been to the last few KubeCons, you know that software supply chain security is a super hot topic. It’s exciting to hear that the release process for Kubernetes now complies with level 1 of the SLSA (Supply-chain Levels for Software Artifacts). Many people and organizations depend on Kubernetes, and these improvements are timely.
There are many other new features in the release and others that graduated to beta and GA. The new
kubectl events command is an alpha feature that addresses some of the limitations of
kubectl get events. The v2 Horizontal Pod Autoscaler API has graduated to GA. There’s also a new feature to defend against logging secrets, a change to make the CRI v1 API the default for the Kubelet, and many more improvements.
There are some deprecations and API changes in 1.23. You can view the complete list in the changelog. The Deprecated API Migration Guide is a great document for navigating these kinds of changes when upgrading. It’s worth bookmarking.
Shout out to the SIG Release team once again for all of their hard work to ship 1.23. Release management is hard and often thankless work, and I appreciate their efforts so much. Also, I want to give a big thank you to everyone who contributed to 1.23. When I see such a long list of changes, it’s clear that many people worked hard to get them done.
We have three new Kubernetes releases to look forward to in 2022. You can see the schedule here.