$ docker run -d -v /var/run/docker.sock:/var/run/docker.sock --name dnsdock -p 172.17.42.1:53:53/udp tonistiigi/dnsdock
$ docker logs dnsdock
2015/03/25 02:25:30 Error connecting to docker socket: Get http://unix.sock/v1.15/containers/json?all=0&size=0: dial unix /var/run/docker.sock: permission denied. Are you trying to connect to a TLS-enabled daemon without TLS?
docker package
docker.x86_64 0:1.5.0-1.el7