I really don't know how to use nova.conf to do it, the service_host seems to be a mandatory parameter for the `nova baremetal-node-create` command.

$ nova help baremetal-node-create
usage: nova baremetal-node-create [--pm_address <pm_address>]
                                  [--pm_user <pm_user>]
                                  [--pm_password <pm_password>]
                                  [--terminal_port <terminal_port>]
                                  <service_host> <cpus> <memory_mb> <local_gb>
                                  <prov_mac_address>
...

I could make it easier for the user making the `setup-baremetal` script to call the `get-vm-hostname` script tho.