Helper function for iSCSI
Require TGT to be installed, as well as open-iscsi.
If used in container, open-iscsi need to be installed on the host.
This library is good enough for:
- Start/stop a iscsi target using tgt, with certain backstores. This can be done inside container.
- Start/stop a iscsi initiator on the host, connect to a target then create the device.