csi-driver-manila-operator

Manila CSI driver operator

An operator to deploy the Manila CSI driver in OpenShift.

Design

The operator is based on openshift/library-go. It manages ClusterCSIDriver instance named manila.csi.openstack.org and runs several controllers in parallel:

• manilaController: Talks to OpenStack API and checks if Manila service is provided.
  • If Manila service is found:
    • It starts manilaControllerSet: Runs csidriverset.Controller that installs the Manila CSI driver itself.
    • It starts nfsController: Runs csidriverset.Controller that installs NFS CSI driver itself.
    • It creates StorageClass for each share type reported by Manila and periodically syncs them at least once per minute, in case a new share type appears in Manila.
    • It never removes StorageClass if Manila service or share type disappears. It may be temporary OpenStack ir Manila re-configuration hiccup.
  • If there is no Manila service, it marks the ClusterCSIDriver instance with ManilaControllerDisabled: True condition. It does not stop any CSI drivers started when Manila service was present! This allows pod to at least unmount their volumes.
• secretSyncController: Syncs Secret provided by cloud-credentials-operator into a new Secret that is used by the CSI drivers. The drivers need OpenStack credentials in different format than provided by cloud-credentials-operator.

The operator is deployed and managed by another operator, the Cluster Storage Operator. You can find the manifests that this operator uses here.

The operator makes few assumptions about the namespace where it runs:

• OpenStack cloud credentials are in Secret named cloud-credentials in the same namespace where the operator runs. The operator uses the credentials to check if Manila is present in the cluster and, since OpenStack does not allow any fine-grained access control, it lets the CSI driver to use the same credentials.
• If underlying OpenStack uses self-signed certificate, the operator expects the certificate is present in a ConfigMap named "cloud-provider-config" with key "ca-bundle.pem" in the namespace where it runs. Generally, it should be a copy of "openshift-config/cloud-provider-config" ConfigMap. It then uses the certificate to talk to OpenStack API.
• The operand (= the CSI driver) must run in the same namespace as the operator, for the same reason as above - it uses the same self-signed OpenStack certificate, if provided.