This tutorial shows how to create a QCOW2 image that can be directly imported via virt-install to test out Fedora 22 Atomic starting from a custom OStree repo. The process involves composing an OStree repository from a Fedora Atomic tree definition, serving it over HTTP so the installer can reach it, then driving an unattended installation through a kickstart file. This gives you full control over the package set and tree composition rather than relying on a pre-built official image.