[PATCH/RFC 0/4] Providing mechanism to list available repositories

I'm working on a project that has separate Git repositories for
different components.  Repositories are cloneable via
  git clone git@xvm.mit.edu:path/to/repo.git,
where the 'git' user's shell is git-shell.

We have been seeking a simple and maintainable way for users to discover the set of available repositories. E.g. posting the list on our website would add extra steps for users to find and retrieve the list as well as require extra effort from our end. Since we already give users ssh access to git@xvm.mit.edu, we would like to multiplex the functionality to allow discovery of available repositories.

Our solution is to expose a 'list' command to the end user, invocable
as
  ssh git@xvm.mit.edu list,
which displays the available repositories.

We find this mechanism useful in that it requires no extra infrastructure on either our end or the user's end. Our implementation is extensible, allowing the system administrator to place arbitrary commands in ~/git-shell-commands (if the directory is omitted, no extra functionality is exposed), and also supports an interactive mode.

What do people think of this approach? I'd love to get this functionality merged in some form.

Thank you!

Greg Brockman