These are files containing cloud images of the Debian GNU/Linux
operating system designed for OpenStack. The files in this
directory are specifically for the
If your platform supports the EC2 style metadata server (which is contacted by cloud-init), and also supports an HDD image (using either raw or qcow2 format), then most likely it will work. Note that it will not work on Amazon EC2 if you are not using the HVM mode.
Debian Jessie is no longer supported by the Debian Cloud Team, as official security support for it ended in June 2018. We strongly recommend that users should move on to use Stretch (Debian 9) instead, our current stable release.
If you understand the lack of support and still have a strong need for a Jessie image, they are still available for download - see the "archive" directory.
Other questions can be forwarded to the OpenStack packaging team: debian-openstack at lists.debian.org.