We want to use systemd for managing the lifetime of OpenVPN. Take
the debian generator (which should work with busybox ash) and the
openvpn.service (to inhibit the sysvinit script) and the target
file and install it.
On systems that have ran "update-rc.d openvpn defaults" one need
to manually execute a systemctl enable openvpn.service. This is
not done through a post-inst script and I am not sure if we should
do it. This means there is a danger of ending with a unit that
doesn't start OpenVPN automatically after upgrade!
The scripts/packages have not been tested on a device yet.
Holger Hans Peter Freyther