Gitaly running on own server instructions are not complete

In the gitaly documentation explain accurately how to run a gitaly in a different server that gitlab.

However, in the document, there's no place to explain how to run gitlab-shell in another server, because, installing gitaly implies to install gitlab-shell as dependency.

So, please could you clarify this point because I solved this issue:

• sharing the .gitlab_shell_secret file

• modifying unicorc.rb adding listen "IP_GITLAB_SERVER:8080

• in /etc/gitlab-shell/config.yml setting:

  gitlab_url: "http://GITLAB_SERVER:8080/"

However, I don't feel comfortable with this solution because I don't really understand the need of installing gitlab-shell with gitaly.