Week Ending September 21, 2025

Developer News

Ray Wainman shared that he is stepping down as co-lead of SIG Autoscaling, and Adrian Moisey will step into the role alongside Jack Francis.

From the SIG K8s Infra leaders Davanum Srinivas (@dims) and Benjamin Elder (@bentheelder) are stepping down and nominating Ciprian Hacman (@hakman) and Dylan Page (@GenPage) as new chairs.

Release Schedule

Next Deadline: PRR Freeze, October 9

The Kubernetes v1.35 release cycle has officially started and we are now collecting enhancements. Work with your SIG leads to get a lead-opted-in label for your KEPs to get them added to the v1.35 cycle.

Please note that the PRR Freeze is a hard deadline starting v1.35. You can read more about the PRR Freeze deadline here and the exception process here.

Other Merges

Replace HandleCrash with HandleCrashWithContext in apiserver — adds contextual logging
Add case-insensitive DNS subdomain validation via k8s-long-name-caseless format — lets long names be validated without forcing lower case
Enable declarative validation for DeviceClass type in resource APIs and resource APIs (v1, v1beta1, v1beta2) — validation-gen tags + tests.
Ensure cacher and etcd3 use consistent key schema requirements
Add RunWithContext variant to EstablishingController — enables context-aware cancellation and richer logging for controller actions
Use iifname in kube-proxy’s nftables mode for interface matching — improves correct filtering by interface name.
Add k8s-label-key & k8s-label-value formats for declarative validation — enables using those formats in +k8s:format= tags so label keys/values are validated automatically
Honor KUBEADM_UPGRADE_DRYRUN_DIR during kubeadm upgrades
Replace WaitForNamedCacheSync with WaitForNamedCacheSyncWithContext in pkg/controller/ and pkg/controller/garbagecollector
Add fine-grained metrics to distinguish declarative validationmismatches & panics — includes a validation_identifier label for better diagnostics.
Add metric for StatefulSet MaxUnavailable violations — tracks when availability drops below spec’s threshold
Enforce API conventions for Conditions fields — ensures metav1.Condition is used and markers/tags follow standard format
Make admission & pod-security admission checks respect emulation version
Add proper goroutine management in kube-controller-manager to prevent leaks
Update MutatingAdmissionPolicy storage version to use v1beta1

Promotions

Graduate ControlPlaneKubeletLocalMode to GA in kubeadm

Deprecated

Set the deprecated version to 1.34.0 for apiserver_storage_objects metric
Remove automaxprocs workaround now that Go 1.25 manages GOMAXPROCS automatically

Version Updates

golangci-lint to v2.4.0
go language version upgraded to v1.25
system-validators to v1.11.1
Bump Go to 1.25.1, update dependencies & distroless iptables images

Subprojects and Dependency Updates

etcd v3.6.5 fixes lease renewals, snapshot/defrag corruption, removes a flag, builds with Go 1.24.7
kubebuilder v4.9.0 upgrades deps, updates Helm CRDs, fixes Docker builds and CRD handling
prometheus v3.6.0 adds PromQL duration funcs, new TSDB blocks API, OTLP/tracing tweaks, bug fixes
vertical-pod-autoscaler v1.5.0 makes In-Place Updates Beta, deprecates Auto mode, adds metrics, supports K8s 1.34

Last Week In Kubernetes Development (LWKD) is a product of multiple contributors participating in Kubernetes SIG Contributor Experience. All original content is licensed Creative Commons Share-Alike, although linked content and images may be differently licensed. LWKD does collect some information on readers, see our privacy notice for details.

You may contribute to LWKD by submitting pull requests or issues on the LWKD github repo.