Should provide a working install of GNU Mediagoblin in the /mediagoblin subdirectory of your RI-HTTP site. No guarantees, especially for other sites, but this can work nicely as reference code.
$ sudo ./install_deps.sh
$ sudo ./create_user.sh
$ # set up mail server
$ sudo apt-get install postfix
(Select "internet site" and the proper site name)
$ # set up PostGRE
$ sudo -u postgres createuser mediagoblin
(answer every question with 'n' for no)
$ sudo -u postgres createdb -E UNICODE -O mediagoblin mediagoblin
$ sudo ./setup_repo.sh
$ sudo -u mediagoblin `pwd`/deploy.sh
$ sudo ./deploy_celery.sh
$ sudo -u mediagoblin ./upgrade.sh