This is a teamcity build agent docker image, it uses docker in docker from https://github.com/jpetazzo/dind to allow you to start docker images inside of it :) When starting the image as container you must set the TEAMCITY_SERVER environment variable to point to the teamcity server e.g.
docker run -e TEAMCITY_SERVER=http://localhost:8111
Optionally you can specify your ownaddress using the TEAMCITY_OWN_ADDRESS variable.
docker run -d --name=teamcity-agent-1 --link teamcity:teamcity --privileged -e TEAMCITY_SERVER=http://teamcity:8111 sjoerdmulder/teamcity-agent:latest