This is a helper script designed to integrate OpenVPN with the systemd-resolved service via DBus instead of trying to override /etc/resolv.conf, or manipulate systemd-networkd configuration files.

Since systemd-229, the systemd-resolved service has an API available via DBus which allows directly setting the DNS configuration for a link. This script makes use of busctl from systemd to send DBus messages to systemd-resolved to update the DNS for the link created by OpenVPN.