def info(self):
        """return information about replica set"""
        hosts = ','.join(x['host'] for x in self.members())
        mongodb_uri = 'mongodb://' + hosts + '/?replicaSet=' + self.repl_id
        result = {"id": self.repl_id,
                  "auth_key": self.auth_key,
                  "members": self.members(),
                  "mongodb_uri": mongodb_uri,
                  "orchestration": 'replica_sets'}
        if self.login:
            # Add replicaSet URI parameter.
            uri = ('%s&replicaSet=%s'
                   % (self.mongodb_auth_uri(hosts), self.repl_id))
            result['mongodb_auth_uri'] = uri
        return result
return information about replica set