Check for an available name and return that to the caller.

def _container_registration(self, alias):
        """
        Check for an available name and return that to the caller.
        """
        containers = Container.find_by_name(self._client_session, alias)

        def validate_name(name):
            valid = True
            if name in containers:
                valid = False

            return valid

        count = 1
        container_name = "{0}-0{1}".format(alias, count)
        while not validate_name(container_name):
            count += 1
            container_index = count if count > 10 else "0{0}".format(count)
            container_name = "{0}-{1}".format(alias, container_index)

        return container_name