Helm Controller is used by Mirantis Container Cloud to handle management, regional, and managed clusters core addons such as StackLight and the application addons such as the OpenStack components.
Before Container Cloud 2.19.0, to support Helm v2 releases, the Tiller process runs in the same Pod as Helm Controller. The Tiller gRPC endpoint is not accessible outside the Pod.
Since Container Cloud 2.19.0, Helm v2 is not supported and Tiller is removed.
Helm Controller is installed as a separate Helm v3 chart by the Container
Cloud provider. Its Pods are created using
The Helm release information is stored in the
KaaSRelease object for
the management and regional clusters and in the
for all types of the Container Cloud clusters.
These objects are used by the Container Cloud provider.
The Container Cloud provider uses the information from the
ClusterRelease object together with the Container Cloud API
Cluster spec. In
Cluster spec, the operator can specify
the Helm release name and charts to use.
By combining the information from the
ClusterRelease object, the cluster actuator generates
the LCMCluster objects. These objects are further handled by LCM Controller
and the HelmBundle object handled by Helm Controller.
HelmBundle must have the same name as the LCMCluster object
for the cluster that HelmBundle applies to.
Although a cluster actuator can only create a single HelmBundle per cluster, Helm Controller can handle multiple HelmBundle objects per cluster.
Helm Controller handles the HelmBundle objects and reconciles them with the state of Helm in its cluster.
Helm Controller can also be used by the management cluster with corresponding HelmBundle objects created as part of the initial management cluster setup.