Just started using systemd and need to stop and start OpenVPN.I can successfully start OpenVPN with this for example:systemctl start openvpn@vpn1.serviceand can stop it with:systemctl stop openvpn@vpn1.serviceHowever I'd like to be able to stop openvpn within a script without having to know which VPN is currently connected. Previously I would use:service stop openvpnIs this possible using systemctl? 
systemd: Stop all OpenVPN processes
systemd;openvpn
You can use patterns (including shell globs) with systemctl commands. See man systemctl:shell-style globs will be matched against currently loaded units; literal unit names, with or without a suffix, will be treated       as in the first case. This means that literal unit names always refer to exactly one unit, but globs may match zero units and this is not considered       an error.       Glob patterns use fnmatch(3), so normal shell-style globbing rules are used, and *, ?, [] may be used. See glob(7) for more details. The       patterns are matched against the names of currently loaded units, and patterns which do not match anything are silently skipped. For example:                 # systemctl stop sshd@*.service       will stop all sshd@.service instances.So, in your case: systemctl stop openvpn* should stop all OpenVPN services.