@wsgi.response(202)
    @wsgi.action('createImage')
    @common.check_snapshots_enabled
    def _action_create_image(self, req, id, body):
        """Snapshot a server instance."""
        context = req.environ['nova.context']
        entity = body.get("createImage", {})

        image_name = entity.get("name")

        if not image_name:
            msg = _("createImage entity requires name attribute")
            raise exc.HTTPBadRequest(explanation=msg)

        props = {}
        metadata = entity.get('metadata', {})
        common.check_img_metadata_properties_quota(context, metadata)
        try:
            props.update(metadata)
        except __HOLE__:
            msg = _("Invalid metadata")
            raise exc.HTTPBadRequest(explanation=msg)

        instance = self._get_server(context, req, id)

        bdms = objects.BlockDeviceMappingList.get_by_instance_uuid(
                    context, instance.uuid)

        try:
            if self.compute_api.is_volume_backed_instance(context, instance,
                                                          bdms):
                policy.enforce(context,
                        'compute:snapshot_volume_backed',
                        {'project_id': context.project_id,
                        'user_id': context.user_id})
                image = self.compute_api.snapshot_volume_backed(
                                                       context,
                                                       instance,
                                                       image_name,
                                                       extra_properties=props)
            else:
                image = self.compute_api.snapshot(context,
                                                  instance,
                                                  image_name,
                                                  extra_properties=props)
        except exception.InstanceInvalidState as state_error:
            common.raise_http_conflict_for_instance_invalid_state(state_error,
                        'createImage', id)
        except exception.Invalid as err:
            raise exc.HTTPBadRequest(explanation=err.format_message())

        # build location of newly-created image entity
        image_id = str(image['id'])
        url_prefix = self._view_builder._update_glance_link_prefix(
                req.application_url)
        image_ref = common.url_join(url_prefix,
                                    context.project_id,
                                    'images',
                                    image_id)

        resp = webob.Response(status_int=202)
        resp.headers['Location'] = image_ref
        return resp
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/api/openstack/compute/legacy_v2/servers.py/Controller._action_create_image