Wraps rpm-ostree compose tree a container.
Today, it mostly implements a YAML → JSON conversion for the treefiles, as I view the use of JSON as a mistake for various reasons.
Usage example:
host# podman run --privileged --rm -v /var/srv:/srv quay.io/cgwalters/coreos-assembler
# cd /srv && coreos-assembler --repo=repo --cachedir=cache host.yml
The container image is built in OpenShift CI.