Kubernetes 1.9 was announced today, bringing customers of the open source container orchestration system stable tools for running important applications. This should make it more attractive for enterprises and other businesses that have been waiting for a guarantee of stability.
In particular, the release, which is expected in a week, has moved Kubernetes’ Workloads APIs to stable, meaning that the tools for running stateful applications, deployments, sets of daemons, and replicas are all essentially complete and will not break with future iterations of the system. That’s a key milestone for development and IT organizations that have balked at deploying applications using those features because they were marked as beta and subject to change.
The Kubernetes project has committed to maintaining the APIs that they mark as stable, so customers can now safely rely on StatefulSets, Daemon Sets, Replica Sets, and Deployments. In addition, the release team was able to change the defaults for some of these systems in order to bring them in line with best practices that were uncovered over the beta periods for each feature.
A criticism of Kubernetes is that in the past the project has changed features too significantly for large organizations to rely on it. Making Workloads stable should help with some of those concerns, since the APIs bundled in that group are critical for applications like running databases on top of Kubernetes.
In addition, the new release comes with beta support for running Windows containers, a key feature for some enterprise users. Developers will still have a Linux control plane for managing the Windows pods inside a Kubernetes cluster, but those who want to write applications targeting a Windows environment will be able to do so.
The third major feature with this release is alpha support for the Container Storage Interface, which is designed to make it easier for developers and platform owners to plug different types of storage into a Kubernetes cluster. This means customers can programmatically choose different providers for storing data that is used by an application running on top of Kubernetes.
Creating a storage interface makes it easier for a wide variety of providers to ensure their offerings are compatible with Kubernetes without working through the project itself to bake that support into the main open source project.
This news comes at a critical time for Kubernetes as a project. All of the major cloud providers now offer a managed service for running multi-container applications on top of their infrastructure using Kubernetes. Making these features stable is an important step in addressing the needs of customers of those services.
Correction 12/8: This story has been corrected to clarify that Kubernetes 1.9 is expected to release on December 13.