First of all you need to create the game folder with the Wurm Unlimited Dedicated Server tool in Steam (you will find it under Library - tools in Steam). Make sure to get the external and internal IP right, or the server won't start. Adjust the settings to your liking and copy the files to the </path/to/game/folder> mentioned below.
You will find the files under your Steam folder "steamapps\common\Wurm Unlimited Dedicated Server\Adventure" (if you used the "Adventure" folder as template).
More info about server settings and ports here:
How to create:
docker create \
--name wurm \
-e SUID=<UID> -e SGID=<GID> \
-v </path/to/game/folder>:/opt/steam/wurm/server \
The SUID and SGID are the UID/GID for the user having rights to the game folder.
To find this information, type: id <username>
I highly recommend not to use root user (it will probably fail anyways).
</path/to/game/folder> is the path for the game folder you created with the Dedicated Server tool in Steam.
Start the docker image by running: docker start wurm
To connec to to shell: docker exec -it wurm /bin/bash
To look at real time logs: docker logs -f wurm
To update the server: (no longer possible, I will have to update image here first)
-19. Sep 2017 - Fixed problem if SUID was anything other than 1000
-12. Nov 2017 - Added mod support (ago1024 modloader). Added 3 mods: digtoground, bounty (for killing mobs), inbreedwarning. I had to remove updating of the Wurm server when restarting the docker container to make this work. Will add some options for this later.