The Dockerfile can be found here.
Based of Debian:Jessie, the image pulls the latest Tonido archive and unpacks it and pulls libjpeg8 from a backport and installs that as well.
The dockerfile gives you the option of setting a root password so you'll need to build it yourself to do that.
docker run --name tonido-data -d -p 10001:10001 -v /path-on-host/tonido:/home/tonido -it digitalapotheosis/tonido:latest
To create a data container and then
docker run --rm --volumes-from tonido-data -p 20002:10001 -v /path-on-host/tonido:/home/tonido -it -d digitalapotheosis/tonido:latest
To run it.
As you can see I suggest sharing a host volume.
I wrote a more detailed blog post which can be found here.