Exploring Kubernetes v133 Octarine Key Features Enhancements and Technical Insights

Introduction to Kubernetes v1.33 “Octarine”

Kubernetes v1.33, codenamed “Octarine”, continues the evolution of the world’s most widely adopted container orchestration platform. With a strong focus on improving developer productivity, operational simplicity, and extending cloud-native capabilities, this release introduces stable features, beta enhancements, and exciting alpha previews.

This blog post covers the major changes and improvements in v1.33, highlights new APIs, and addresses important technical FAQs to help you confidently understand and adopt the release.

Key Features and Enhancements

Sidecar Container Lifecycle Management (GA)

One of the long-awaited features, sidecar container lifecycle support, has finally reached General Availability (GA) in v1.33. This feature allows containers within a Pod to have more coordinated startup and shutdown behaviors.

• Highlights: Sidecars can be marked as non-primary containers. Kubernetes respects the startup and shutdown order of init, main, and sidecar containers. Helps improve observability, log collection, and service mesh proxies (e.g., Envoy).
• Use Case: Injecting a logging sidecar (like Fluent Bit) that continues to process logs after the main app container exits.

ReadWriteOncePod PersistentVolume Access Mode (GA)

The ReadWriteOncePod (RWO-P) volume access mode, initially introduced as alpha in v1.22, is now GA.

• Highlights: Ensures exclusive volume access by a single Pod. Prevents accidental multi-attach issues in StatefulSets. Supports CSI drivers and dynamically provisioned volumes.
• Use Case: Stateful apps like PostgreSQL or MySQL that require exclusive disk access.

Node System Swap Support (Beta)

Linux swap support has always been a hot topic in Kubernetes. In v1.33, Kubernetes introduces controlled swap support at the node level in Beta.

• Highlights: – Admins can allow system swap with fine-grained control. Reduces node pressure for low-priority workloads. Configurable via kubelet flags.
• Caveats: Swap can introduce unpredictability; caution is advised.

Kubernetes Gateway API (Beta)

Kubernetes’ long-term goal of replacing Ingress with a more extensible API sees a leap forward. Previously, in alpha, the Gateway API matured to Beta in v1.33.

• Highlights: – Defines GatewayClass, Gateway, HTTPRoute, and TCPRoute Supports advanced traffic routing use cases (e.g., weighted traffic splitting). Integrates well with service meshes and external gateways.
• Use Case: Canary deployments using HTTPRoute with weighted backends.

Container Resource-Based Scheduling (Alpha)

• A new alpha feature in v1.33 enables scheduling decisions based on container-level resource requests rather than Pod-level aggregates.
• Highlights: Useful in multi-container Pods where only one container is resource-intensive. Allows better bin-packing and node utilization. Requires enabling the ContainerResourceBasedScheduling feature gate.

Deprecations and Removals

Every Kubernetes release sunsets legacy or unused features. Here’s what you should be aware of in v1.33:

• PodSecurityPolicy (PSP): Fully removed. Use alternatives like OPA/Gatekeeper or Kyverno.
• Beta APIs deprecated: Several APIs, like batch/v1beta1 for CronJobs, were removed; migrate to batch/v1.
• dockershim: Was already deprecated in earlier releases and is now completely removed from kubelet.

Action Required: Audit your cluster API usage using kubent or pluto tools.

Performance and Security Improvements

Performance:

Recent improvements have significantly enhanced Kubernetes performance in large-scale environments. Scheduler throughput has been optimized for clusters with over 5,000 nodes, enabling faster and more efficient pod placement. Additionally, API server caching for Custom Resource Definitions (CRDs) has been improved, which reduces the load on etcd and boosts overall system responsiveness. Control plane components also benefit from faster startup times, contributing to quicker cluster initialization and recovery.

Security:

The latest updates enhance Kubernetes security and observability. All control plane components now support TLS 1.3 by default, strengthening encryption and communication security. Audit logs have been improved to include container image digests, providing better traceability and helping to ensure image integrity. Additionally, Role-Based Access Control (RBAC) has been refined with more granular permissions for ephemeral containers, allowing for more precise and secure access control during debugging and troubleshooting.

Upgrading to Kubernetes v1.33

Before You Upgrade:

To prepare for upcoming Kubernetes changes and maintain cluster stability, reviewing and updating deprecated APIs is important to avoid future compatibility issues. Additionally, ensure that your CSI drivers support ReadWriteOncePod (RWO-P) volumes, as this volume access mode is increasingly used in modern workloads. Finally, validate your Custom Resource Definitions (CRDs) and webhook configurations to ensure they comply with current Kubernetes standards and function correctly with evolving APIs.

Upgrade Strategy:

For a reliable and safe Kubernetes upgrade, it’s essential to begin by backing up your etcd data and overall cluster state to prevent data loss in case of issues. The upgrade process should start with the control plane nodes, followed by the worker nodes, to maintain cluster stability. To minimize risk and enable smoother rollouts, consider using blue/green or canary deployment strategies for node groups, allowing you to test updates on a subset of nodes before applying changes cluster-wide.

Final Thoughts

Kubernetes v1.33 “Octarine” is a balanced release that continues to refine existing primitives while pushing the ecosystem forward. From long-awaited sidecar lifecycle controls to smarter volume and traffic management, this release caters to operators and developers.

Whether you’re running production clusters or sandbox environments, it’s worth exploring the features, understanding the impacts, and planning your upgrade accordingly.

Drop a query if you have any questions regarding Octarine and we will get back to you quickly.

About CloudThat