'Read the domain specific configuration files and load the drivers.
Domain configuration files are stored in the domain config directory,
and must be named of the form:
keystone.<domain_name>.conf
For each file, call the load config method where the domain_name
will be turned into a domain_id and then:
- Create a new config structure, adding in the specific additional
options defined in this config file
- Initialise a new instance of the required driver with this new config'

def _setup_domain_drivers_from_files(self, standard_driver, resource_api):

    conf_dir = CONF.identity.domain_config_dir
    if (not os.path.exists(conf_dir)):
        LOG.warning('Unable    to    locate    domain    config    directory:    %s', conf_dir)
        return
    for (r, d, f) in os.walk(conf_dir):
        for fname in f:
            if (fname.startswith(DOMAIN_CONF_FHEAD) and fname.endswith(DOMAIN_CONF_FTAIL)):
                if (fname.count('.') >= 2):
                    self._load_config_from_file(resource_api, [os.path.join(r, fname)], fname[len(DOMAIN_CONF_FHEAD):(- len(DOMAIN_CONF_FTAIL))])
                else:
                    LOG.debug('Ignoring    file    (%s)    while    scanning    domain    config    directory', fname)
