Container Engine for Kubernetes now supports Kubernetes version 1.25.12, in addition to versions 1.27.2 and 1.26.7. With the availability of support for Kubernetes version 1.25.12, Container Engine for Kubernetes will cease support for Kubernetes version 1.25.4 on October 13, 2023. Oracle strongly recommends you immediately upgrade clusters to Kubernetes version 1.25.12.

Note the following:

• Support for Kubernetes version 1.25.12 addresses an issue found in Container Engine for Kubernetes support for Kubernetes version 1.25.4 (see Worker node status unexpectedly changes to NotReady when running Oracle Linux 8.7 or Oracle Linux 8.8 with Kubernetes version 1.24.1, 1.25.4, or 1.26.2).
• Although Kubernetes version 1.25.4 will not be supported after October 13, 2023, it might continue to be available for selection. However, Oracle strongly recommends you upgrade clusters to Kubernetes version 1.25.12.

To upgrade a cluster to a new Kubernetes minor version:

1. Upgrade the Kubernetes version running on the control plane by following the instructions in Upgrading the Kubernetes Version on Control Plane Nodes in a Cluster.
2. Having upgraded the control plane, upgrade the Kubernetes version running on worker nodes in a node pool by following the instructions in Upgrading the Kubernetes Version on Worker Nodes in a Cluster.

Note:

Always follow the Kubernetes skew policy for Kubernetes minor version support.

Example skew policy:

• Kubernetes control plane nodes are at version 1.27.2
• Kubernetes worker nodes must be at version 1.27.2, 1.26.7, or 1.25.12

Note that although the worker nodes in a node pool must follow the Kubernetes skew policy, you do not have to upgrade them one minor version at a time.

For more information, see Upgrading Clusters to Newer Kubernetes Versions.