Comment 1 for bug 1873331

The view mysql_innodb_cluster_metadata.v2_this_instance references performance_schema.global_variables which the mysqlrouter user does not have permissions for.

 v2_this_instance | CREATE ALGORITHM=UNDEFINED DEFINER=`clusteruser`@`10.5.0.4` SQL SECURITY INVOKER VIEW `v2_this_instance` AS select `i`.`cluster_id` AS `cluster_id`,`i`.`instance_id` AS `instance_id`,`c`.`cluster_name` AS `cluster_name`,`c`.`cluster_type` AS `cluster_type` from (`v2_instances` `i` join `clusters` `c` on((`i`.`cluster_id` = `c`.`cluster_id`))) where (`i`.`mysql_server_uuid` = (select convert(`performance_schema`.`global_variables`.`VARIABLE_VALUE` using ascii) from `performance_schema`.`global_variables` where (`performance_schema`.`global_variables`.`VARIABLE_NAME` = 'server_uuid'))) | utf8mb4 | utf8mb4_0900_ai_ci |

Adding charmhelpers to the bug. Needs: "GRANT SELECT ON performance_schema.global_variables"