Add a record to pg_hba.conf.

def add_hba_entry(self, *, type='host', database, user, address=None,
                      auth_method, auth_options=None):
        """Add a record to pg_hba.conf."""
        status = self.get_status()
        if status == 'not-initialized':
            raise ClusterError(
                'cannot modify HBA records: cluster is not initialized')

        if type not in {'local', 'host', 'hostssl', 'hostnossl'}:
            raise ValueError('invalid HBA record type: {!r}'.format(type))

        pg_hba = os.path.join(self._data_dir, 'pg_hba.conf')

        record = '{} {} {}'.format(type, database, user)

        if type != 'local':
            if address is None:
                raise ValueError(
                    '{!r} entry requires a valid address'.format(type))
            else:
                record += ' {}'.format(address)

        record += ' {}'.format(auth_method)

        if auth_options is not None:
            record += ' ' + ' '.join(
                '{}={}'.format(k, v) for k, v in auth_options)

        try:
            with open(pg_hba, 'a') as f:
                print(record, file=f)
        except IOError as e:
            raise ClusterError(
                'cannot modify HBA records: {}'.format(e)) from e