Is it possible to add/commit a file to the index of a local bare Git repo?

I'm messing around with the Ruby Git gem... seeing how I can use it to manage/access a Gitosis server I'm running. Does anyone know if it is possible to add/commit files to a local bare repo, or will I need to set up a local 'normal' repo and use SSH to push it to the bare repo on the localhost?

You should be able to do this using low level plumbing commands:

$ generate_contents | git hash-object -t blob -w --stdin
$ git update-index --cacheinfo 100644 sha1 path

• sha1 is result of previous command.
• 100644: means an ordinary file.

But bare repositories are meant to be used only to push into or fetch from. Bare repository doesn't need to have index at all!