Helper to cache the config XML and raise a CommandExecutionError if we fail
    to do so. If we successfully cache the file, return the cached path.

def _retrieve_config_xml(config_xml, saltenv):
    '''
    Helper to cache the config XML and raise a CommandExecutionError if we fail
    to do so. If we successfully cache the file, return the cached path.
    '''
    ret = __salt__['cp.cache_file'](config_xml, saltenv)

    if not ret:
        raise CommandExecutionError('Failed to retrieve {0}'.format(config_xml))

    return ret