OpenVPN: bug in /etc/hotplug.d/iface/42-openvpn

This file was added as a part of https://gitlab.labs.nic.cz/turris/turris-os-packages/-/merge_requests/148 .

$ ACTION=ifup DEVICE=pppoe-wan /etc/hotplug.d/iface/42-openvpn
/etc/hotplug.d/iface/42-openvpn: line 24: [: service_is_running: unary operator expected

And I see these errors in syslog every time I connect to the internet/restart network.

The test command ([) is misused: https://gitlab.labs.nic.cz/turris/turris-os-packages/-/blob/master/net/openvpn-hotplug/files/openvpn.hotplug#L24 . The if should use directly the command without the test command - this is how if works. The current behavior results in if [ 0 ], which is incorrect syntax.

Change line 24 to

if service_is_running "openvpn" &&

and the script will work.