openstack-service support for @instance services

[apevec]

(copied from https://bugzilla.redhat.com/show_bug.cgi?id=1394689 )

$ sudo openstack-service restart Failed to restart [email protected]: Unit name [email protected] is missing the instance name. See system logs and 'systemctl status [email protected]' for details.

$ systemctl status [email protected] Failed to get properties: Unit name [email protected] is missing the instance name.

I have 3 services running that belog to zaqar: openstack-zaqar.service [email protected] system-openstack\x2dzaqar.slice