Build and run it:
for v in 6 7; do
docker build -t libressl-centos$v-rpm:latest CentOS$v/
docker run -ti --rm \
-v $PWD/CentOS$v/data:/data \
-v $PWD/CentOS$v/assets/config:/config \
libressl-centos$v-rpm:latest start.sh
done
Find the RPM's in de data folder:
$ ls CentOS*/data/