OpenKruise 1.8 Release Highlights: In‑Place VPA, StatefulSet Volume Expansion, AI WorkloadSpread, Serverless Probe, SidecarSet Gray‑Release, and Helm Pre‑Delete Hook

OpenKruise, an open‑source cloud‑native application automation suite under CNCF, released version 1.8 in February 2025, bringing several major enhancements for Kubernetes workloads.

In‑Place Vertical Pod Autoscaling (VPA) : integrates the Alpha‑stage InPlacePodVerticalScaling feature of Kubernetes 1.27, allowing CPU and memory adjustments without pod recreation, with guidance on enabling the feature and its current limitations.

Advanced StatefulSet volume expansion : adds native in‑place PVC expansion for Advanced StatefulSet, eliminating manual PVC updates and supporting seamless storage scaling.

WorkloadSpread for AI workloads : introduces targetFilter to apply WorkloadSpread to workloads that do not implement the Scale sub‑resource, such as TFJob, enabling multi‑region and elastic scheduling.

Serverless PodProbeMarker : extends custom probe support to serverless pods via annotations, allowing health checks without the Kruise‑Daemon.

SidecarSet gray‑release : adds injectionStrategy with revision control and partial rollout percentages for fine‑grained sidecar updates.

Helm pre‑delete hook : protects against accidental removal of Kruise CRDs and resources by checking for remaining custom resources before uninstall.

Example YAML configurations are provided:

apiVersion: apps.kruise.io/v1alpha1
kind: CloneSet
spec:
  template:
    spec:
      containers:
      - name: example-container
        resources:
          requests:
            memory: "512Mi"
            cpu: "500m" # 1 -> 500m / 2
  updateStrategy:
    type: InPlaceIfPossible

apiVersion: apps.kruise.io/v1beta1
kind: StatefulSet
spec:
  volumeClaimUpdateStrategy:
    type: OnPodRollingUpdate
  volumeClaimTemplates:
    - spec:
        resources:
          requests:
            storage: 2Gi # 1Gi -> 2Gi
        storageClassName: allow-volume-expansion

apiVersion: apps.kruise.io/v1alpha1
kind: WorkloadSpread
spec:
  targetRef:
    apiVersion: kubeflow.org/v1alpha1
    kind: TFJob
    name: tfjob-demo
  targetFilter:
    selector:
      matchLabels:
        role: worker
    replicasPathList:
    - spec.tfReplicaSpecs.Worker.replicas

apiVersion: apps.kruise.io/v1alpha1
kind: SidecarSet
metadata:
  name: sidecarset
spec:
  injectionStrategy:
    revision:
      revisionName: revision-a
      policy: Partial
  updateStrategy:
    partition: 70%

The release also outlines a future roadmap (versions 1.9, 2.0, 2.1) and invites community contributions through GitHub, Slack, DingTalk, and WeChat.