thing.py

def cert_path_to_lineage(config):
    # If config.cert_path is defined, find an appropriate value for config.certname
    # by searching through available files in config.renewal_configs_dir, and finding
    # one with an appropriate value for 'fullchain'.

    # pylint: disable=unused-argument
    def update_cert_name_for_cert_path_match(candidate_lineage, rv):
        """ Return the lineagename or return None. """
        options = [candidate_lineage.fullchain_path, candidate_lineage.chain_path, 
                os.path.join(candidate_lineage.archive_dir, os.path.basename(config.cert_path[0]))]
        if config.cert_path[0] in options:
            return candidate_lineage.lineagename

    cert_path_match = _search_lineages(config, update_cert_name_for_cert_path_match, None)
    if not cert_path_match:
        error_msg = "Could not find a matching lineage for the cert_path {0}"
        raise errors.Error(error_msg.format(config.cert_path[0]))
    else:
        return cert_path_match