How to config SSH for gitlab?

If you followed Installation Instructions of gitlab, then you must have installed it on an linux box under the user named git. Typically in a folder like this

/home/git/gitlab 

Hence you should use [email protected]

I am not sure what you mean by "configuring SSH". But since each user is expected to use her own keypair, there should be no problem in accessing gitlab managed repo's using normal git commands. Both the following should work

git clone ssh://[email protected]/group/repo.git
git clone [email protected]:group/repo.git

Each user must have set their own git identity (on their local machines) using

git config --global user.name "elitmus"
git config --global user.email "[email protected]"

so that git can uniquely identify each user.

In my experience, I had to connect to the gitlab server, as the git user, and modify the authenticated_keys file, as it was filled with a bunch of random #'s. after clearing that, I added my SSH key in the GitLab GUI and was able to clone and push normally.

Hope that helps.