T4930 has introduced a bug where if no wireguard interfaces are defined, the vyos-domain-resolver process exists with failure.
We need to implement a check in vyos-domain-resolver to see if output of dict_search_args is NoneType before attempting to iterate.
```
[edit]
vyos@vyos# set firewall group domain-group test address vyos.dev
[edit]
vyos@vyos# commit
[edit]
vyos@vyos# sudo systemctl status vyos-domain-resolver
× vyos-domain-resolver.service - VyOS firewall domain resolver
Loaded: loaded (/lib/systemd/system/vyos-domain-resolver.service; disabled; preset: enabled)
Active: failed (Result: exit-code) since Sat 2025-01-25 12:26:50 GMT; 214ms ago
Duration: 257ms
Process: 3268 ExecStart=/usr/bin/python3 -u /usr/libexec/vyos/services/vyos-domain-resolver (code=exited, status=1/FAILURE)
Main PID: 3268 (code=exited, status=1/FAILURE)
CPU: 250ms
Jan 25 12:26:50 vyos systemd[1]: vyos-domain-resolver.service: Scheduled restart job, restart counter is at 5.
Jan 25 12:26:50 vyos systemd[1]: Stopped vyos-domain-resolver.service - VyOS firewall domain resolver.
Jan 25 12:26:50 vyos systemd[1]: vyos-domain-resolver.service: Start request repeated too quickly.
Jan 25 12:26:50 vyos systemd[1]: vyos-domain-resolver.service: Failed with result 'exit-code'.
Jan 25 12:26:50 vyos systemd[1]: Failed to start vyos-domain-resolver.service - VyOS firewall domain resolver.
```
```
def update_interfaces(config, node):
if node == 'interfaces':
wg_interfaces = dict_search_args(config, 'wireguard')
peer_public_keys = {}
# for each wireguard interfaces
for interface, wireguard in wg_interfaces.items():
peer_public_keys[interface] = []
```