Run Docker commands without sudo

Run Docker commands without sudo
1. Add the docker group if it doesn't already exist
$ sudo groupadd docker
2. Add the connected user $USER to the docker group
Optionally change the username to match your preferred user.

$ sudo gpasswd -a $USER docker
3. Restart the docker daemon
$ sudo service docker restart
If you are on Ubuntu 14.04-15.10, use docker.io instead:

$ sudo service docker.io restart