From https://www.digitalocean.com/community/articles/how-to-install-mongodb-on-ubuntu-12-04
apt-key adv --keyserver keyserver.ubuntu.com --recv 7F0CEB10 echo "deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen" | tee -a /etc/apt/sources.list.d/10gen.list apt-get -y update apt-get -y install mongodb-10gen