'Return data about the given server group.'

@extensions.expected_errors(404)
def show(self, req, id):

    context = _authorize_context(req, 'show')
    try:
        sg = objects.InstanceGroup.get_by_uuid(context, id)
    except nova.exception.InstanceGroupNotFound as e:
        raise webob.exc.HTTPNotFound(explanation=e.format_message())
    return {'server_group': self._format_server_group(context, sg, req)}
