Does not work, if host uses cgroup v2

[jan-di]

The container cannot determine its own id, to connect with the docker network.

See more details here: https://stackoverflow.com/questions/68816329/how-to-get-docker-container-id-from-within-the-container-with-cgroup-v2

[jan-di]

In the new solution, the container get its own ID by searching for the image specific label via the docker api. This means for now, that only one instance of the backup service can run on the docker host. This could by circumvented by another setting, where you can set a unique id/name per backup service, but this is not planned at the moment.