When adopting networkers:

https://docs.redhat.com/en/documentation/red_hat_openstack_services_on_openshift/18.0/html-single/adopting_a_red_hat_openstack_platform_17.1_deployment/index#adopting-networker-services-to-the-data-plane_data-plane

In Step1: Deploy the OpenStackDataPlaneNodeSet CR for your nodes:

The example nodeset is incorrect as it lacks the next 2 flags:

          edpm_network_config_nmstate: false
          edpm_bootstrap_network_resolvconf_update: false 

Wihout edpm_bootstrap_network_resolvconf_update, resolv.conf in the networker is empty and it fails in the install-os dataplane service.

For info, those 2 flags are included in the nodeset example when adopting the compute nodes.