Update notes

This section describes the specific actions you as a cloud operator need to complete before or after your Container Cloud cluster update to the Cluster releases 17.3.6, 16.3.6, or 16.4.1.

Consider the information below as a supplement to the generic update procedures published in MOSK Operations Guide: Automatic upgrade of a management cluster and Update to a patch version.

Pre-update actions

Update managed clusters to Ubuntu 22.04

Management cluster update to Container Cloud 2.29.1 will be blocked if at least one node of any related managed cluster is running Ubuntu 20.04, which reaches end-of-life in April 2025. Moreover, in Container Cloud 2.29.0, the Cluster release update of the Ubuntu 20.04-based managed clusters became impossible, and Ubuntu 22.04 became the only supported version of the operating system.

Therefore, ensure that every node of all your managed clusters are running Ubuntu 22.04 to unblock management cluster update in Container Cloud 2.29.1 and managed cluster update in Container Cloud 2.29.0.

For the update procedure, refer to Mirantis OpenStack for Kubernetes documentation: Bare metal operations - Upgrade an operating system distribution.

Note

Existing management clusters were automatically updated to Ubuntu 22.04 during cluster upgrade to the Cluster release 16.2.0 in Container Cloud 2.27.0. Greenfield deployments of management clusters are also based on Ubuntu 22.04.

Post-update actions

Migration of container runtime from Docker to containerd

Since Container Cloud 2.28.4, Mirantis introduced an optional migration of container runtime from Docker to containerd, which is implemented for existing management and managed bare metal clusters. This migration becomes mandatory in the scope of Container Cloud 2.29.x. Otherwise, the management cluster update to Container Cloud 2.30.0 will be blocked.

The use of containerd allows for better Kubernetes performance and component update without pod restart when applying fixes for CVEs. For the migration procedure, refer to MOSK Operations Guide: Migrate container runtime from Docker to containerd.

Important

Container runtime migration involves machine cordoning and draining.