/etc/os-net-config/config.json is empty on controller/compute in RHOSP 11

Issue

• Prior to RHOSP 11, the config file /etc/os-net-config/config.json used to be populated with the expected network configuration:

[stack@undercloud-0-rhosp11 os-net-config]$ cat config.json 
{"network_config": [{"addresses": [{"ip_netmask": "192.0.2.1/24"}], "mtu": 1500, "ovs_extra": ["br-set-external-id br-ctlplane bridge-id br-ctlplane"], "members": [{"dns_servers": [], "type": "interface", "name": "eth1", "primary": "true", "mtu": 1500}], "type": "ovs_bridge", "name": "br-ctlplane"}]}

• With RHOSP 11, we observe that /etc/os-net-config/config.json is empty on the controller and compute nodes:

[stack@undercloud-0-rhosp11 os-net-config]$ cat config.json 
[stack@undercloud-0-rhosp11 os-net-config]$