Fedora images are unsupported images. This means that we don't provide any guarantees or support on the software within the image but we'd like you to have the option to use the image in OpenStack Deployments. Unsupported images are a category in the New Server deploy wizard in the Skyline OpenStack Interface.
The image currently deployed in OpenStack is Fedora 22. See the Fedora anouncement page for detailed information.
The Fedora Base Cloud image is taken directly from (https://getfedora.org/en/cloud/). It is the latest stable Fedora release, 64 bit, prepared with cloud-init.
You need to login with the user "fedora". This user is allowed to sudo without password. Openstack will, if available and selected, place your key under that user.
Upgrading from older image
From Fedora 21 and up you can upgrade the Fedora installation by using the FedUp package.
See the Fedora wiki for more information: https://fedoraproject.org/wiki/FedUp