Tag a remote git repository without cloning it

Question

Is there a way to tag a remote git repository without having cloned it locally?

In order to correlate a code repository with a config repository, I want to

Answer 1

It's possible to tag the current commit at the tip of a branch remotely, but not (as far as I can tell) with git porcelain or plumbing. We'll have to speak to a remote git receive-pack directly.

Here's some python that uses dulwich to do what we want:

#!/usr/bin/env python

from dulwich.client import get_transport_and_path
import sys


def tag_remote_branch(repo_url, branch, tag):
    client, path = get_transport_and_path(repo_url)

    def determine_wants(refs):
        tag_ref_name = 'refs/tags/%s' % tag
        branch_ref_name = 'refs/heads/%s' % branch
        # try not to overwrite an existing tag
        if tag_ref_name in refs:
            assert refs[tag_ref_name] == refs[branch_ref_name]
        refs[tag_ref_name] = refs[branch_ref_name]
        return refs

    # We know the other end already has the object referred to by our tag, so
    # our pack should contain nothing.
    def generate_pack_contents(have, want):
        return []

    client.send_pack(path, determine_wants, generate_pack_contents)


if __name__ == '__main__':
    repo_url, branch, tag = sys.argv[1:]
    tag_remote_branch(repo_url, branch, tag)