Easy peasy question: According to
https://docs.openstack.org/nova/rocky/admin/availability-zones.html, I
can specify the host I want to use by following the format

 --availability-zone ZONE:HOST

So, let's get the hostnames for the compute nodes.

[raub@test-hn ~(keystone_admin)]$ openstack compute service list
--service nova-compute
+----+--------------+-----------------------+------+---------+-------+----------------------------+
| ID | Binary       | Host                  | Zone | Status  | State |
Updated At                 |
+----+--------------+-----------------------+------+---------+-------+----------------------------+
| 11 | nova-compute | compute02.example.com | nova | enabled | up    |
2021-02-03T17:25:53.000000 |
| 12 | nova-compute | compute03.example.com | nova | enabled | up    |
2021-02-03T17:25:53.000000 |
| 13 | nova-compute | compute01.example.com | nova | enabled | up    |
2021-02-03T17:25:52.000000 |
+----+--------------+-----------------------+------+---------+-------+----------------------------+
[raub@test-hn ~(keystone_admin)]$

I want to use compute01.example.com, which I can resolve to 10.1.1.11.
But, when I try to create server with (running as admin):

openstack server create \
--image default_centos_8 \
--flavor m1.small \
--key-name raubkey \
--availability-zone nova:compute01.example.com \
--nic net-id=LONG_BORING-ID \
raub-netest

I get the error message (from openstack server show raub-netest|grep fault):

'message': 'No valid host was found. No such host - host:
compute01.example.com node: None '

What am I doing wrong here?