Starting additional OpenVPN connection under systemd

Question

I have a couple of OpenVPN connections to various servers that are autostarted when I log into my laptop. Other connections, to production servers, have to be set up manually. Until recently I ran Ubuntu 14.04, where I could run things like

sudo service openvpn start production-server-21

to add a connection. Since upgrading to Ubuntu 16.04, and systemd, this no longer works. Is there still a simple way to add a connection or do I have to

cd /etc/openvpn
sudo openvpn --config production-server-21.conf &

which is much less nice (can't use full path for config file, as it contains relative references to keys/certs).

Answer 1

It turns out that

sudo service openvpn@production-server-21 start

works, as well as something similar to what @meuh suggested in their comment:

sudo systemctl start openvpn@production-server-21