The setup needs a "datapump" to initially load data into the virtuoso from a git repository and to regularly or on update dump the changes to the git repository.
I could be integrated like that into the docker-compose file
datapump:
image: datapump
container_name: pfarrerbuch_datapump
environment:
volumes:
- /data/pfarrerbuch/models:/models
links:
- virtuoso
Maybe this is a candidate: https://github.com/Dockerizing/virtuoso-import-docker