def METHOD_NAME(id):
    updated_tar = request.files["file"]
    message = request.form["commit_message"]
    repo_path = app.config["model"].repository_path(id)
    repo_tar_path = repo_path + ".tar.gz"
    if not os.path.exists(repo_path):
        os.makedirs(repo_path)
    updated_tar.save(repo_tar_path)
    tar = tarfile.open(repo_tar_path, "r:gz")
    try:
        tar.extractall(repo_path)
    finally:
        tar.close()
    _modify_repository(repo_path)
    return json.dumps({"message": message})