Managing Kubernetes clusters

Kubernetes clusters are created and managed by self-service users, as described in "Managing Kubernetes clusters" in the Self-Service Guide. In the admin panel, you can view Kubernetes cluster details, view master and worker groups, update the Kubernetes version, and delete Kubernetes clusters.

Additionally, you can change the Kubernetes parameters such as the size and storage policy of the system volume on master nodes. The system volume is used by the Kubernetes management services and etcd. The new parameters will be applied only in new Kubernetes clusters. System volumes in existing Kubernetes clusters will retain their previous parameters. To improve the stability of Kubernetes clusters, it is highly recommended to select a storage policy with an SSD-based tier.

Virtuozzo Hybrid Infrastructure uses the soft anti-affinity policy for Kubernetes cluster nodes. According to this policy, Kubernetes nodes are distributed across compute nodes by groups: master nodes are distributed separately from workers. In this case, a compute node can host both a master node and a worker node. However, if there are not enough compute nodes to evenly distribute Kubernetes nodes from the same group, some of them can be placed on one compute node.

Limitations

• Kubernetes version 1.15.x. is no longer supported. Kubernetes clusters created with this version are marked with the Deprecated tag and cannot be updated to newer versions.
• You cannot manage Kubernetes clusters in the admin panel during an update.

Prerequisites

• The compute cluster is created, as described in Creating the compute cluster.
• The Kubernetes service is installed during the compute cluster deployment or later, as described in Provisioning Kubernetes clusters.

To view the details of a Kubernetes cluster

On the Compute > Kubernetes screen, click a Kubernetes cluster to open its right pane.

To change the Kubernetes service parameters

1. Click Settings on the Kubernetes clusters screen.

2. Set the desired storage policy and size for the system volume, and then click Done.

   

To view master and worker groups

1. On the Compute > Kubernetes screen, click a Kubernetes cluster.
2. On the cluster right pane, navigate to the Groups tab.
3. List all of the nodes in a group by clicking the arrow icon next to the required node group.

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 non-disruptive update will start. The Kubernetes nodes will be updated one by one, with the data availability unaffected. If high availability is enabled for the master node, the Kubernetes API will stay available during an update.

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

To delete a Kubernetes cluster

1. On the Compute > Kubernetes screen, click a Kubernetes cluster.
2. On the cluster right pane, click Delete.