Some helpful code snippets if you use docker containers (written October 2015 so adjust for the fact that things change over time.

# reinstall docker-gen-proxy
docker run -d -p 80:80 -v /var/run/docker.sock:/tmp/docker.sock:ro jwilder/nginx-proxy

# make nano work
export TERM=xterm

# dockers won't start
nano /var/lib/docker
# add this line exactly
DOCKER_OPTS="--storage-driver=aufs"

# restart dockers
sudo docker start $(docker ps -a -q)