The Mirantis Container Cloud Release Controller is responsible for the following functionality:
Monitor and control the
ClusterReleaseobjects present in a management cluster. If any release object is used in a cluster, the Release Controller prevents the deletion of such an object.
ClusterReleaseobjects published at https://binary.mirantis.com/releases/ with an existing management cluster.
Trigger the Container Cloud auto-upgrade procedure if a new
KaaSReleaseobject is found:
Search for the managed clusters with old Cluster releases that are not supported by a new Container Cloud release. If any are detected, abort the auto-upgrade and display a corresponding note about an old Cluster release in the Container Cloud web UI for the managed clusters. In this case, a user must update all managed clusters using the Container Cloud web UI. Once all managed clusters are upgraded to the Cluster releases supported by a new Container Cloud release, the Container Cloud auto-upgrade is retriggered by the Release Controller.
Trigger the Container Cloud release upgrade of all Container Cloud components in a management cluster. The upgrade itself is processed by the Container Cloud provider.
Trigger the Cluster release upgrade of a management cluster to the Cluster release version that is indicated in the upgraded Container Cloud release version. The LCMCluster components, such as MKE, are upgraded before the HelmBundle components, such as StackLight or Ceph.
Verify the regional cluster(s) status. If the regional cluster is ready, trigger the Cluster release upgrade of the regional cluster.
Once a management cluster is upgraded, an option to update a managed cluster becomes available in the Container Cloud web UI. During a managed cluster update, all cluster components including Kubernetes are automatically upgraded to newer versions if available. The LCMCluster components, such as MKE, are upgraded before the HelmBundle components, such as StackLight or Ceph.
The Operator can delay the Container Cloud automatic upgrade procedure for a limited amount of time or schedule upgrade to run at desired hours or weekdays. For details, see Schedule Mirantis Container Cloud upgrades.
Container Cloud remains operational during the management and regional clusters upgrade. Managed clusters are not affected during this upgrade. For the list of components that are updated during the Container Cloud upgrade, see the Components versions section of the corresponding Container Cloud release in Release Notes.
Due to the known issue 24802 affecting clusters with enabled proxy, the Container Cloud release upgrade from 2.17.0 to 2.18.0 can trigger automatic update of managed clusters to the latest available Cluster releases in their respective series. For details, see the known issue 24802.
When Mirantis announces support of the newest versions of Mirantis Container Runtime (MCR) and Mirantis Kubernetes Engine (MKE), Container Cloud automatically upgrades these components as well. For the maintenance window best practices before upgrade of these components, see MKE Documentation.