In August 2024, the Kubernetes 1.31.0 update was released, a version that brings with it significant advances in system stability, performance and security.
In this article, we’ll walk you through the key features of this release, discuss potential challenges, provide helpful deployment tips, and share additional observations relevant to cluster administrators and developers.
Kubernetes 1.31 Development Phases: Stable, Beta and Alpha
Kubernetes 1.31 introduces new features that are in different phases of development: stable, beta and alpha.
Each of these phases indicates the degree of maturity and stability of the introduced features.
Stable Characteristics
Node Memory Swapping Support: In Kubernetes 1.31, Linux node memory swapping support has reached the stable phase.
This enhancement enables better memory management, optimizing resource usage and improving overall cluster performance.
Automatic Scaling Based on Container Resources: The horizontal scaling of pods based on container resource metrics has become stable, allowing for more precise configuration of automatic scaling based on individual container resource usage.
Beta Features
Structured Authorization Configuration: This feature, now in beta, facilitates the management of permissions and access within the Kubernetes cluster through a more structured configuration of the authorization chain.
This enhancement allows for more flexible and detailed administration of security policies.
Routing Preferences for Services: Introduces the ability to specify routing preferences, such as preferClose, which prioritizes sending traffic to endpoints within the same zone as the client, reducing latency and network costs.
Alpha Characteristics
Alpha features represent the most experimental features in the Kubernetes development cycle.
These features are designed to be tested by advanced users who wish to experiment with new features prior to production availability.
Because of their experimental nature, alpha features can be unstable and are subject to significant changes.
Their deployment in mission-critical environments is not recommended until they have reached more mature stages.
Comparison of What’s New in Kubernetes 1.31 with Previous Releases
Kubernetes 1.31.0 introduces enhancements that represent a significant improvement over previous versions.
Previous versions of Kubernetes did not include enhancements such as support for on-node memory swapping and automatic scaling based on container resources as stable features.
These innovations represent a significant advance over previous versions.
Dynamic Resource Allocation Changes in Kubernetes 1.31
In Kubernetes 1.31, significant changes have been introduced to dynamic resource allocation, focused on implementing structured parameters to improve system efficiency.
These changes address existing issues related to third-party resource management and optimize how resources are allocated within the cluster.
Possible Challenges in Kubernetes 1.31.0
Implementation Complexity: While Kubernetes 1.31.0 introduces significant enhancements, integrating these new features can be complex.
Necessary adjustments to the existing configuration can be challenging, especially for administrators with limited Kubernetes experience.
Community Dependency: As open source software, Kubernetes relies on its community for ongoing support and development.
In situations where immediate support is required, this dependency can be a drawback.
Challenges for Novice Administrators: Administrators with less experience with Kubernetes may face a significant learning curve when trying to implement and tune new features.
Tips for Deploying Kubernetes 1.31.0
Proactive Updating: It is recommended to upgrade clusters to the latest supported version to take advantage of performance and security improvements.
Kubernetes offers standard support for 14 months for each release.
Exhaustive Testing: Before deploying Kubernetes 1.31.0 in production, it is crucial to perform extensive testing in development environments.
Kubernetes deletions and major changes in v1.31
In addition to new features, Kubernetes 1.31.0 introduces important changes related to the removal and deprecation of certain features to maintain the health of the project.
Removing the status.nodeInfo.kubeProxyVersion FieldThe field .status.nodeInfo.kubeProxyVersion field The number of nodes has been deprecated in this version because the information provided was unreliable.
This change paves the way for its removal in future versions.
Elimination of In-Tree Integrations with Cloud Providers
As part of an effort to externalize all integrations with cloud providers, Kubernetes 1.31 marks the removal of the latest in-tree integrations.
This forces users to use external drivers, reinforcing the neutrality of Kubernetes.
Flag removal –keep-terminated-pod-volumes
The kubelet flag –keep-terminated-pod-volumesdeprecated since 2017, has finally been removed.
Administrators should ensure that their configurations do not depend on this flag.
CephFS and Ceph RBD Volume Plugin Removal
The CephFS and Ceph RBD volume plugins have been removed, and the use of the corresponding CSI drivers is recommended.
This transition is part of the ongoing effort to migrate to CSI-based volume management.
Deprecation of non-CSI Volume Limit PluginsVersion 1.31 also removes several non-CSI based volume limit plugins, recommending migration to the NodeVolumeLimits plugin for better management.SHA-1 Security and Support
In line with the changes in Go 1.18, Kubernetes 1.31 moves towards removing support for SHA-1 signed certificates, which will be completely incompatible in future releases.
It is recommended to migrate to more secure signing methods.
Additional Comments
Kubernetes 1.31.0 continues to advance resource management and system security, demonstrating the community’s commitment to the robustness and efficiency of the container orchestrator.
The continued evolution of Kubernetes reinforces its position as a leading container orchestration platform and underscores the importance of staying current with the latest releases and enhancements.
Conclusions
Kubernetes 1.31.0 not only offers significant improvements in terms of functionality and security, but also marks an important step in removing obsolete features and transitioning to new practices and technologies.
In future releases, such as Kubernetes 1.32, more API and feature removals are planned, underscoring the need to stay informed and prepared to perform necessary cluster migrations.
Administrators and developers must be prepared to adapt to these changes and take advantage of the new opportunities offered by this release.
