as part of migration support, the clusterID has to be fetched
from passed in mon. Because the intree RBD storage class only
got monitor and not `clusterID` parameter support. However, in
CSI, SC has the `clusterID` parameter support but not mon. Due
to that we have to fetch the clusterID from config file for the
passed in mon and use it in our operations. This adds a helper
function to retrieve clusterID from passed in mon string.
Updates https://github.com/ceph/ceph-csi/issues/2509
Signed-off-by: Humble Chirammal <hchiramm@redhat.com>
1f5963919f