# Version control systems support

Kallithea supports Git and Mercurial repositories out-of-the-box. For Git, you do need the `git` command line client installed on the server.

You can always disable Git or Mercurial support by editing the file `kallithea/__init__.py` and commenting out the backend.

    BACKENDS = {
        'hg': 'Mercurial repository',
        #'git': 'Git repository',
    }

## Git support

### Web server with chunked encoding

Large Git pushes require an HTTP server with support for chunked encoding for POST. The Python web servers waitress and gunicorn (Linux only) can be used. By default, Kallithea uses waitress for paster serve instead of the built-in paste WSGI server.

The paster server is controlled in the .ini file:

    use = egg:waitress#main

or:

    use = egg:gunicorn#main

Also make sure to comment out the following options:

    threadpool_workers =
    threadpool_max_requests =
    use_threadpool =

## Mercurial support

### Working with Mercurial subrepositories

This section explains how to use Mercurial subrepositories in Kallithea.

Example usage:

    ## init a simple repo
    hg init mainrepo
    cd mainrepo
    echo "file" > file
    hg add file
    hg ci --message "initial file"

    # clone subrepo we want to add from Kallithea
    hg clone http://kallithea.local/subrepo

    ## specify URL to existing repo in Kallithea as subrepository path
    echo "subrepo = http://kallithea.local/subrepo" > .hgsub
    hg add .hgsub
    hg ci --message "added remote subrepo"

In the file list of a clone of `mainrepo` you will see a connected subrepository at the revision it was cloned with. Clicking on the subrepository link sends you to the proper repository in Kallithea.

Cloning `mainrepo` will also clone the attached subrepository.

Next we can edit the subrepository data, and push back to Kallithea. This will update both repositories.