Docker not found/working

> root@forum:~# cat /etc/os-release
> NAME="Ubuntu"
> VERSION="14.04.5 LTS, Trusty Tahr"
> ID=ubuntu
> ID_LIKE=debian
> PRETTY_NAME="Ubuntu 14.04.5 LTS"
> VERSION_ID="14.04"
> HOME_URL="http://www.ubuntu.com/"

> root@forum:~# lsb_release -a
> No LSB modules are available.
> Distributor ID:	Ubuntu
> Description:	Ubuntu 14.04.5 LTS
> Release:	14.04
> Codename:	trusty