Updating Kubernetes clusters

When a new Kubernetes version becomes available, you can update your Kubernetes cluster to it. An update is non-disruptive for Kubernetes worker nodes, which means that these nodes are updated one by one, with the data availability unaffected. The Kubernetes API will be unavailable during an update, unless high availability is enabled for the master node.

Starting from a Kubernetes cluster update to version 1.24.3, Kubernetes virtual machines are re-created based on a newer Fedora CoreOS image. Such a rolling update is used to preserve the cluster data. Before starting the update, you need to make sure that the compute cluster has enough resources and quotas for at least one extra VM of the largest flavor used by your Kubernetes cluster. If the master and worker node flavors differ, then you should take into account the largest one of them.

Limitations

  • You cannot update Kubernetes clusters with versions 1.15.x–1.17.x to newer versions.
  • You cannot manage Kubernetes clusters in the self-service panel during an update.

Prerequisites

To update a Kubernetes cluster

  1. Click a Kubernetes cluster that is marked with the Update available tag.
  2. On the Kubernetes cluster pane, click Update in the Kubernetes version field.
  3. In the Update window, select a Kubernetes version to update to and follow the provided link to read about API resources that are deprecated or obsoleted in the selected version. Then, click Update.
  4. In the confirmation window, click Confirm. The update process will start.

    Do not manage Kubernetes virtual machines during the update as it may lead to disruption of the update process and cluster inoperability.