Conducting rolling upgrades
By default, Kubernetes clusters created with Gardener in Cleura Cloud are upgraded automatically. Those upgrades take place during a specified maintenance window, and you may find out more about what they involve and how they work. Besides the automatic upgrades, you can manually apply any upgrades available for your cluster.
In the following two examples, we first show how to manually upgrade the machine image the cluster nodes are based on and then how to upgrade the Kubernetes version the cluster uses.
Upgrading machine images
In the left-hand vertical pane of the Cleura Cloud Management Panel, select Containers → Gardener. In the central pane, you will see all your Gardener clusters, each on its own row. If a Kubernetes upgrade is available, in the Versions column you will notice a triangular marker together with the new Kubernetes version. On the other hand, if there is a new machine image version for the cluster nodes, then in the Workers column you will notice just a triangular marker and no version number.
To get more information about the new machine image available, click on the cluster row to bring its details into view, then select the Worker Groups tab. There, you will see the version of the new machine image. To start the upgrade process, click any of the two icons.
The upgrade process will start immediately and will take some time to complete. After it is done, there will be no triangular marker in the Workers column, and the new image version will be displayed in the Worker groups tab. Our example still has a triangular marker in the Version column. That is because we have not upgraded Kubernetes yet.
To get the Kubernetes upgrade process going, click the orange icon on the right of the cluster row. In the pop-up menu that appears, you will notice an option named Kubernetes Patch Available. That one is not always there, but now it is and acts as another indicator of an available Kubernetes upgrade. Please select the option by clicking on it.
A new pop-up window named Upgrade Kubernetes Version for: <cluster_name> appears. From the Version drop-down menu, you may select the new Kubernetes version you want your cluster to upgrade to. When ready, click the blue Upgrade button to start the process.
After some minutes, the upgrade will be over. The new Kubernetes version will be visible in the Version column of the cluster row.