'Parse the label part of the meta_host definition
if it has a wild card it gets expanded into a list
of all matching labels, e.g.: 2*label* becomes
2*label1 2*label2 2*label3'

def _parse_meta_host_labels(self, label):

    if label.endswith('*'):
        labels = self.execute_rpc('get_labels', name__startswith=label.rstrip('*'))
        if (len(labels) == 0):
            self.failure(('No    labels    matching    %s' % label), item=label, what_failed='Failed    to    find    labels')
        return [l['name'] for l in labels]
    else:
        return [label]
