Question as in the title. I want to improve our code reviews with tool like gerrit or phabricator. We don't have access to the server hosting our git repository, but we have other server where we can run gerrit or phabricator - depends which one is better/let us do what we want.
First question: is it possible? Second: how to do it?
Phabricator does not need the master copy of a repository. Many installs (including Phabricator's meta-install) currently use it with GitHub, which does not provide access to the master.
This is the only mode Phabricator operates in right now (it can not currently manage masters) so just follow the normal install instructions for configuration, notably:
http://www.phabricator.com/docs/phabricator/article/Diffusion_User_Guide.html