Docker without Sudo

gistfile1.sh

vagrant@vagrant-ubuntu-trusty-64:~$ docker ps -a
2014/10/05 07:08:23 Get http:///var/run/docker.sock/v1.12/containers/json?all=1: dial unix /var/run/docker.sock: permission denied
vagrant@vagrant-ubuntu-trusty-64:~$ sudo gpasswd -a vagrant docker
Adding user vagrant to group docker
vagrant@vagrant-ubuntu-trusty-64:~$ sudo service docker restart
docker: unrecognized service
vagrant@vagrant-ubuntu-trusty-64:~$ sudo service docker.io restart
docker.io stop/waiting
docker.io start/running, process 4628
vagrant@vagrant-ubuntu-trusty-64:~$ docker ps -a
2014/10/05 07:08:53 Get http:///var/run/docker.sock/v1.12/containers/json?all=1: dial unix /var/run/docker.sock: permission denied
vagrant@vagrant-ubuntu-trusty-64:~$ sudo shutdown -r now
vagrant@vagrant-ubuntu-trusty-64:~$
Broadcast message from vagrant@vagrant-ubuntu-trusty-64
	(/dev/pts/0) at 7:09 ...

The system is going down for reboot NOW!
Connection to 127.0.0.1 closed by remote host.
Connection to 127.0.0.1 closed.
 vagrant ssh                                                                                                                                                                                  /tmp/vagrant aquabot
Welcome to Ubuntu 14.04.1 LTS (GNU/Linux 3.13.0-36-generic x86_64)

 * Documentation:  https://help.ubuntu.com/

  System information as of Sun Oct  5 07:09:30 UTC 2014

  System load: 0.0               Memory usage: 9%   Processes:       49
  Usage of /:  3.6% of 39.34GB   Swap usage:   0%   Users logged in: 0

  Graph this data and manage this system at:
    https://landscape.canonical.com/

  Get cloud support with Ubuntu Advantage Cloud Guest:
    http://www.ubuntu.com/business/services/cloud


Last login: Sun Oct  5 07:07:29 2014 from 10.0.2.2
vagrant@vagrant-ubuntu-trusty-64:~$ docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
vagrant@vagrant-ubuntu-trusty-64:~$