Mounting directory from host machine to container in Docker
docker, dotcloud
Solution
Just as a final update, this feature is now released in Docker (though the API has changed since the pull request linked by @imiric).
Simply use a command like
docker run -v /tmp:/root myImage
in order to mount `/tmp` from the host machine as `/root` within the image.
Source: https://docs.docker.com/engine/userguide/dockervolumes/
Problem
How do I mount a directory from the host machine to a container in Docker?