'Retrieve resource information.
This method is called when nova-compute launches, and
as part of a periodic task that records the results in the DB.
:param nodename: the UUID of the node.
:returns: a dictionary describing resources.'

def get_available_resource(self, nodename):

    if (not self.node_cache):
        self._refresh_cache()
    node = self._node_from_cache(nodename)
    return self._node_resource(node)
