Use Hypriot OS (a Raspbian variant) for a working Docker environment on your
Raspberry Pi:

http://blog.hypriot.com/downloads/

Install docker-compose separately:

    sudo apt-get install python-pip
    sudo pip install docker-compose

Now everything should come together:

    docker-compose up

will build and start three different Docker containers

- Teamcity server
- Teamcity build agent
- A MySQL server (which I happen to need for my test suite)

Open http://<host>:8111 to access Teamcity. There are some remaining steps
that you need to do in the web UI, especially authorising the build agent.