This is no longer needed; OPNSense now has full CARP support in the wireguard plugin which works much better than these hacks ever did =] I'll leave it here as an example of a thing you can do and 'cause why delete it?
- Install
checkWireguardas/usr/local/opnsense/scripts/OPNsense/Wireguard/checkWireguard - Install
actions_wireguardCarp.confas/usr/local/opnsense/service/conf/actions.d/actions_wireguardCarp.conf - run
service configd restart