Release Controller

The MOSK Release Controller is responsible for the following functionality:

  • Monitor and control the KaaSRelease and ClusterRelease objects present in a management cluster. If any release object is used in a cluster, the Release Controller prevents the deletion of such an object.

  • Sync the KaaSRelease and ClusterRelease objects published at https://binary.mirantis.com/releases/ with an existing management cluster.

  • Trigger the managementc cluster auto-update procedure if a new KaaSRelease object is found:

    1. Search for MOSK clusters with old Cluster releases that are not supported by a new KaaSRelease. If any are detected, abort the auto-update and display the corresponding note about an old Cluster release in the MOSK management console. In this case, a user must update all MOSK clusters to the Cluster releases supported by a new KaaSRelease for the auto-update to be retriggered by the Release Controller.

    2. Trigger the KaaSRelease update of all components in the management cluster. The update itself is processed by the bare metal provider.

    3. Trigger the ClusterRelease update of the management cluster to the Cluster release version that is indicated in the updated KaaSRelease version. The LCMCluster components, such as MKE, are updated before the HelmBundle components, such as StackLight or Ceph.

      Once the management cluster is updated, an option to update managed clusters becomes available in the MOSK management console. During a managed cluster update, all cluster components including Kubernetes are automatically updated to newer versions if available. The LCMCluster components, such as MKE, are updated before the HelmBundle components, such as StackLight or Ceph.

The Operator can delay the automatic update procedure for a limited amount of time or schedule update to run at desired hours or weekdays. For details, see Schedule Mirantis Container Cloud updates.

MOSK remains operational during the management cluster update. MOSK clusters are not affected during this update. For the list of components that are updated during the management cluster update, see the Components versions section of the corresponding major Container Cloud release in Container Cloud Release Notes: Container Cloud releases.

When Mirantis announces support of the newest versions of Mirantis Container Runtime (MCR) and Mirantis Kubernetes Engine (MKE), MOSK automatically upgrades these components as well. For the maintenance window best practices before upgrade of these components, see MKE Documentation.