How to use a PostUp hook to restart WireGuard every few minutes or hours?

[kevinfay]

Dynamic IP addresses
Many users report having to restart WireGuard whenever a dynamic IP changes, as it only resolves hostnames on startup. To force WireGuard to re-resolve dynamic DNS Endpoint hostnames more often, you may want to use a PostUp hook to restart WireGuard every few minutes or hours.

https://github.com/pirate/wireguard-docs#dynamic-ip-addresses

"But I don't know how to implement this PostUp hook. Help me, pls.

[Gryd3]

Here's another resource for you to look into for dynamic DNS solutions : https://github.com/WireGuard/wireguard-tools/blob/master/contrib/reresolve-dns/reresolve-dns.sh

The idea is to use cron or systemd timers to run this every once in a while. There's no need to restart the tunnel, as it can be updated in place. This can be done manually if you intend the tunnel to run 24/7.

Some platforms don't support this, in which case you'll need to be creative in your solution. (eg, windows, RouterOS, Android...)
Automatic tunnel restarts are applicable to remote equipment that is inaccessible, or has no local-users that can toggle the tunnel or restart the device.

As for the PostUp hook itself.. you could just brute-force it:
= sleep 3600; systemctl restart wg-quick@wg0.service