'Return a list of availability zones.'

@db_api.retry_if_session_inactive()
def get_availability_zones(self, context, filters=None, fields=None, sorts=None, limit=None, marker=None, page_reverse=False):

    return [{'state': ('available' if v else 'unavailable'), 'name': k[0], 'resource': k[1], 'tenant_id': context.tenant_id} for (k, v) in self._list_availability_zones(context, filters).items()]
