root@chaos ~ # cat /run/systemd/system/netplan-ovs-cleanup.service
[Unit]
Description=OpenVSwitch configuration for cleanup
DefaultDependencies=no
Wants=ovsdb-server.service
After=ovsdb-server.service
ConditionFileIsExecutable=/usr/bin/ovs-vsctl
Before=network.target
Wants=network.target

[Service]
Type=oneshot
ExecStart=/usr/sbin/netplan apply --only-ovs-cleanup