This document describes the Kubernetes support and KKP versioning itself.
KKP versions are expressed as x.y.z, where x is the major version, y is the minor version, and z is the patch version.
KKP follows the Kubernetes release model and cycle, though for practical reasons releases are a bit delayed to ensure compatibility with Kubernetes. In general, the latest three minor versions of KKP are supported, i.e. 2.19, 2.18 and 2.17. With the release of a new minor KKP version, support for the oldest supported KKP version is dropped.
A KKP minor version supports all Kubernetes versions which were supported upstream at the time of its release. You can find more details about the upstream support policy in the Version Skew Policy.
As time passes, patch versions of KKP will support new patch versions of Kubernetes that have been released since, as well as drop old patch versions if they are affected by critical bugs.
KKP will typically drop support of minor versions of Kubernetes which have gone EOL, even during the lifecycle of a KKP minor version (e.g. from 2.16.1 to 2.16.2). This of course results in any minor version of KKP being eventually limited to two and later one minor version of Kubernetes.
One notable exception is when upgrading from an older version of Kubernetes might require extensive migration of loads running within the updated clusters (e.g. API version deprecations) – in these cases KKP will maintain LIMITED support of an EOL Kubernetes version(s) for an additional release cycle for the purpose of facilitating these migrations.
In the following table you can find the supported Kubernetes versions for the current KKP version.
| KKP version | 1.22 | 1.21 | 1.20* | 1.19** | 1.18** |
|---|---|---|---|---|---|
| 2.19.x | ✓ | ✓ | ✓ | - | - |
| 2.18.x | ✓ | ✓ | ✓ | ✓ | - |
| 2.17.x | - | ✓ | ✓ | ✓ | ✓ |
| 2.16.x | - | - | ✓ | ✓ | ✓ |
* Kubernetes 1.20 is scheduled to reach End-of-Life (EOL) on March 2022.
** Kubernetes 1.18 and 1.19 releases have reached End-of-Life (EOL). We strongly recommend upgrading to a supported Kubernetes release as soon as possible.
Upgrades from a previous Kubernetes version are generally supported whenever a version is marked as supported, for example KKP 2.17 supports updating clusters from Kubernetes 1.18 to 1.21.