Lightweight CalDAV+CardDAV server. http://baikal-server.com/
Original Docker Image Source: https://github.com/ckulka/baikal-docker
This fork basically makes it non-root.
If already installed and Specific directory is present, add the following to the Dockerfile or mount the file into the container.
RUN touch /var/www/baikal/baikal/Specific/ENABLE_INSTALL
# Backup
docker cp baikal:/var/www/Specific/db/db.sqlite db.sqlite
# Restore
docker cp db.sqlite baikal:/var/www/Specific/db/db.sqlite- Add mail ckulka/baikal-docker#32