systemd and non-existent service instances

[Richard Hector <richard@walnut.gen.nz>]

Hi all,

I'm running into a problem with systemd and my openvpn instances.

To start a vpn, I run 'systemctl start openvpn-client@foo_host2' or
similar. That has to be an underscore, because as far as I can see,
using a hyphen/dash will break the instance mechanism. Of course, the
actual hostname has to have a hyphen, because you can't have an
underscore in the DNS.

This means I will inevitably end up typing 'systemctl start
openvpn-client@foo-host2' by mistake.

When that happens, it appears that systemd will try to start it, and
fail because foo-host2.conf doesn't exist - and try for ever. Showing
the status of foo_host2 works fine, of course, so I don't notice until I
look at the logs.

Is this an inherent part of how systemd works, or is there a way to make
it return an error message, rather than silently trying the impossible?

Thanks,
Richard