def distro_uri(distro_name):
    """
    Get distro URI of main ROS distribution files.

    :param distro_name: name of distro, e.g. 'diamondback'
    :returns: the SVN/HTTP URL of the specified distro.  This function should only be used
      with the main distros.
    """
    return (
        'http://svn.code.sf.net/p/ros-dry-releases/code/trunk/distros/%s.rosdistro'
         % distro_name)
