sudo -v
echo deb http://ppa.launchpad.net/cairo-dock-team/ppa/ubuntu  main ## Cairo-Dock-PPA | sudo tee -a /etc/apt/sources.list
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E80D6BF5
sudo apt-get update
sudo apt-get install cairo-dock cairo-dock-plug-ins