Supported Kubernetes Versions

Currently supported versions

Of a given supported minor version, we always offer at least one tested patch version.

Minor Version State Remarks
1.23 supported recommended version
1.22 supported
1.21 supported
1.20 deprecated removal approx. Q3 2022

Upcoming Versions

Minor Version Start of support
1.24 Approx. Q3 2022
1.25 Approx. Q1 2023

Support policy

We aim to always support four Kubernetes minor versions.
The oldest of which will always be deprecated, meaning that it automatically becomes unsupported with the support of a new minor version.

We will not update the Kubernetes version on clusters with unsupported versions.

The Kubernetes project releases three minor versions per year, each with approximately one year of official support. See Kubernetes Releases.
We test new versions and make them available as soon as we can ensure the stability with MetaKube.

FAQ

What does it mean, when a version becomes unsupported?

To support newer versions, we may make changes that are not compatible with unsupported versions.
In order to prevent changes like these to break an unsupported cluster, we may disable updates to that cluster.

The components that make up the cluster will continue to run with their current configuration.
However, until the cluster version is upgraded to a supported version, updates to the cluster may no longer be applied.

Such updates include (non-exhaustive list):

  • Addon installation and updates
  • Updates to cloud credentials
  • RBAC changes
  • SSH key management

Changes made in the UI (or equivalently over the API) may not reflect in the live state of the cluster.

If the cluster is two versions behind any supported version, version upgrades are no longer possible.

Please contact SysEleven Support if you need help upgrading an old cluster or migrating workloads to a new cluster.

Is it safe to upgrade my cluster?

SysEleven takes care of the correct configuration of your cluster's control plane components and plugins (CNI, CSI, Cloud Controller Manager, etc.) and ensures they are compatible with the new version.

Most Kubernetes minor versions are backwards compatible with existing workloads.
While some API versions may be deprecated, they will continue to work, until they are completely removed.

The next minor release of Kubernetes that removes API Versions, is 1.22, so updates to 1.20 and 1.21 are relatively unobtrusive, add features and improve cluster stability.

Your applications may rely on specific API versions to work.
While most open-source applications on Kubernetes support a wide range of Kubernetes versions, they may break with newer versions.
Likewise, newer versions of open-source applications may in turn require newer Kubernetes versions.

We recommend reading the Kubernetes Changelog for the given version and to check the Kubernetes Deprecated API Migration Guide before upgrading.

Furthermore, it's generally wise to test a Kubernetes version upgrade in a dev environment first.

References