Add access to only one git repository via SSH key, not the entire host

Question

on a server, I want to have several git repositories. I want different users (=different SSH keys) to have access to different repositories (think of GitHub).

I know I can add a user's SSH key to authorized_keys on the server. But that would give the user access to all repos.

How can I set this up correctly? How does GitHub do it?

Answer 1

The easiest solution is to install a tool for managing remote access to git repositories, such as:

• Gitlab
• Gitolite
• Gogs

If you're not willing to use any of those options, you can hack something together by binding keys in your authorized_keys file to a specific command (using the command= option) that is a wrapper that validates repository access. This answer has some ideas that might help you get started.