dhcp: T5840: Merge systemd service overrides for kea-ctrl-agent

Default systemd service for kea-ctrl-agent expects
`/etc/kea/kea-api-password` which is not used in
VyOS.

The systemd unit override to remove the condition
does not need to be in a separate (templated and
dynamic) override file and can be merged into the
existing static override file.

src/conf_mode/service_dhcp-server.py

@@ -45,7 +45,6 @@
 config_file = '/run/kea/kea-dhcp4.conf'
 lease_file = '/config/dhcp/dhcp4-leases.csv'
 lease_file_glob = '/config/dhcp/dhcp4-leases*'
-systemd_override = r'/run/systemd/system/kea-ctrl-agent.service.d/10-override.conf'
 user_group = '_kea'
 
 ca_cert_file = '/run/kea/kea-failover-ca.pem'
@@ -395,8 +394,6 @@ def generate(dhcp):
 
             dhcp['high_availability']['ca_cert_file'] = ca_cert_file
 
-        render(systemd_override, 'dhcp-server/10-override.conf.j2', dhcp)
-
     render(ctrl_config_file, 'dhcp-server/kea-ctrl-agent.conf.j2', dhcp, user=user_group, group=user_group)
     render(config_file, 'dhcp-server/kea-dhcp4.conf.j2', dhcp, user=user_group, group=user_group)
 

src/etc/systemd/system/kea-ctrl-agent.service.d/override.conf

@@ -1,6 +1,7 @@
 [Unit]
 After=
 After=vyos-router.service
+ConditionFileNotEmpty=
 
 [Service]
 ExecStart=