Enable systemd-detect-virt to detect OpenStack instance

[wangyuhang]

We are using dracut on an OpenStack Nova to build images. dracut will call `systemd-detect-virt` to determine whether it is working on a virtual machine. Currently, systemd-detect-virt can't figure out OpenStack correctlly.

I have made a PR on upstream systemd (https://github.com/systemd/systemd/pull/23117), but some detail information are needed. I don't know the difference between OpenStack Nova and OpenStack Compute.

Is it suffisient to determine it's a virtual machine if we can grep `OpenStack` from /sys/class/dmi/id/product_name

[Balazs Gibizer (balazs-gibizer)]

OpenStack Nova is the name of the product while OpenStack Compute is the name of the project (group of people) maintaining OpenStack Nova and related packages. I think it is OK to grep for 'OpenStack' in the dmi as that string is set by OpenStack Nova via the libvirt.

I'm setting this bug as invalid as this is not a bug. If you have further questions please post to the mailing list[0] or joins to the #openstack-nova channel on the OFTC IRC server[1].

[0]https://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-discuss
[1] https://docs.openstack.org/contributors/common/irc.html