$ curl https://packages.gitlab.com/install/repositories/gitlab/gitlab-ee/script.deb.sh |sudobash 
 
% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
1005232052320052320 --:--:--  0:00:01 --:--:--  4853
Detected operating system as debian/squeeze.
Checking for curl...
Detected curl...
Running apt-get update... done.
Installing debian-archive-keyring which is needed for installing
apt-transport-https on many Debian systems.
Installing apt-transport-https... done.
Installing /etc/apt/sources.list.d/gitlab_gitlab-ee.list...done.
Importing packagecloud gpg key... done.
Running apt-get update... done.
 
The repository is setup! You can now install packages.