Kubernetes 1.33 "Octarine": sidecar containers stable, in-place resize in beta

2025-04-23 · Publisher : Kubernetes · Domain : Cloud & DevOps

On 23 April 2025, Kubernetes 1.33 ships 64 enhancements (18 stable, 20 beta, 24 alpha): native sidecar containers reach stable and in-place pod resizing enters beta.

### Background On 23 April 2025, the release team announces **Kubernetes 1.33 "Octarine"**: **64 enhancements**, including 18 stable, 20 beta, 24 alpha and 2 deprecated or withdrawn. Two changes bear directly on operations: native **sidecar containers** are stable, and **in-place pod resource resizing** enters beta. ### Key facts - Sidecars (KEP-753): implemented as init containers with `restartPolicy: Always`, they start before the application, run for the pod's whole life and stop after the main containers. - Sidecars can use probes (startup, readiness, liveness) and their OOM score is aligned with the main containers. - In-place resize (KEP-1287): alpha in 1.27, beta in 1.33; a pod's CPU and memory change without restarting it. - Also stable: backoff limit per index for indexed Jobs and the Job success policy (`.spec.successPolicy`). - In alpha: a `.kuberc` file to separate kubectl preferences from cluster configuration. ### Why it matters Native sidecars fix a long-standing irritant of service meshes and logging agents: start and stop order, which caused stuck Jobs or lost requests. In-place resizing paves the way for vertical scaling without interruption, useful for databases and batch workloads. It remains in beta: test on non-critical environments before relying on it. The authors also flag several deprecations and removals to read before migrating, and credit hundreds of contributors worldwide. ### Takeaway Two historic Kubernetes irritants, sidecar lifecycle and restarting to resize, move forward.

Tags : Kubernetes, Cloud natif, Conteneurs, Open Source