Where the "basic" components are the rook-ceph-agent and rook-discover DaemonSet.
Info:
* Rook Ceph Discovery DaemonSet is only started after at least one CephCluster has been created!
* Rook Ceph Agent ("Flex driver") was used in earlier Rook Ceph versions for mounting storage, before it a switch to use Ceph CSI driver was made.