Kubernetes v1.28 (Planternetes) Release: New Features, Enhancements, and Deprecations

Release Theme and Logo

Kubernetes v1.28, themed "Planternetes," celebrates the collective effort of thousands of community contributors from diverse backgrounds, likening the release process to a garden that grows, faces challenges, and thrives together.

New Features (Major Themes)

Support for Increased Version Skew between Control Plane and Nodes

Allows testing and scaling by extending the supported skew from n‑2 to n‑3, enabling older node components (kubelet, kube-proxy) to work with newer control‑plane components, which benefits users who upgrade control planes faster than nodes.

Stable Recovery from Non‑Graceful Node Shutdown

Kubernetes now cleans up after nodes that shut down unexpectedly or become unrecoverable, ensuring stateful workloads can restart on other nodes; this feature was unstable before v1.20.

Improved CustomResourceDefinition Validation Rules

Introduces CEL‑based validation expressions directly in CRD schemas, adding optional reason and fieldPath fields for richer error reporting.

ValidatingAdmissionPolicies Promoted to Beta

Provides a CEL‑based alternative to admission‑webhook validation, reducing implementation complexity and enabling custom policy enforcement.

Admission Webhook Match Conditions

Allows specifying CEL match conditions to narrow the scope of admission webhook calls; promoted to beta and enabled by default in v1.28.

Beta Support for Swap Space on Linux Nodes

Enables controlled testing of swap usage on nodes, benefiting both node administrators and application developers.

Hybrid Version Proxy (Alpha)

When clusters run mixed‑version API servers, the proxy transparently forwards requests that a local server cannot serve to a compatible peer, hiding version differences from clients.

Control‑Plane Component Code Re‑organization

Begins modularizing kube‑apiserver code into a new staging repository ( k/apiserver ) for better reuse.

CDI Support for Containers (Alpha)

Standardizes injection of complex devices into containers via the Container Device Interface, leveraging the CRI CDIDevices field.

API‑Aware Sidecar Containers (Alpha)

Introduces an restartPolicy field for init and sidecar containers, allowing more flexible startup and restart behavior.

Automatic Default StorageClass Assignment (Stable)

Kubernetes now automatically assigns a default StorageClass to PVCs lacking a storageClassName , and retroactively applies it to existing PVCs.

Job Pod Replacement Strategies (Alpha)

Adds a field to control whether a new Pod is created immediately after the previous one begins termination or only after full termination, addressing issues for stateful workloads and autoscaling.

Job Retry Backoff Limits with Indexed Allocation (Alpha)

Extends the Job API to support per‑index backoff limits, allowing indexed jobs to continue even if some indices fail.

CRI Container and Pod Metrics Without cAdvisor

Enhances the CRI API to provide pod and container metrics directly, reducing reliance on cAdvisor.

Feature Promotions to Stable

kubectl events

Default StorageClass tracing

Non‑graceful node shutdown

Third‑party device monitoring plugins

Auth API for self‑user attributes

Proxy termination endpoint

Extended DNS configuration

IPTables chain ownership cleanup

Reduced iptables‑restore input size

kubelet pod resource endpoint GA

Extended podresources API for allocatable resources

EndpointSlice Reconciler moved to staging

Deprecations and Removals

Removed: GCE PD CSI migration.

Deprecated: Ceph RBD in‑tree plugin, Ceph FS in‑tree plugin.

Release Notes and Downloads

Full release details are available in the official changelog. The v1.28 binaries can be downloaded from GitHub, and you can get started locally with minikube, kind, or kubeadm.

Release Team

The release was driven by a volunteer community, with Grace Nguyen serving as release lead.

Ecosystem Updates

KubeCon + CloudNativeCon China 2023 (Sept 26‑28, Shanghai) and North America 2023 (Nov 6‑9, Chicago) are upcoming events.

Project Metrics

During the 14‑week v1.28 cycle, 911 companies and 1,440 individuals contributed to the project.

Upcoming Webinar

Join the Kubernetes v1.28 release team on Sep 14 2023 at 10 AM PDT for a live overview of new features, deprecations, and upgrade guidance.

Get Involved

Participate via SIGs, weekly community meetings, the Kubernetes contributor site, Twitter, Discuss, Slack, Server Fault, or by sharing your story on the blog.

References

All cited references are listed in the original document.