Trying to Grant Fails on RDS MySQL

[Carlos Mennens]

I spun up a RDS MySQL instance and by default the instance has defaults with an "admin" user. When I created a new user, I tried the following & don't understand why it failed:

> GRANT ALL PRIVILEGES ON *.* TO 'bottled_water'@'%' WITH GRANT OPTION
[2021-02-11 16:33:00] [28000][1045] (conn=10484533) Access denied for user 'admin'@'%' (using password: YES)

When I do the same on my docker container, it works fine. I'm confused...

mysql> select user, host from mysql.user;
+------------------+-----------+
| user | host |
+------------------+-----------+
| root | % |
| mysql.infoschema | localhost |
| mysql.session | localhost |
| mysql.sys | localhost |
| root | localhost |
+------------------+-----------+
5 rows in set (0.00 sec)

mysql> create user 'tuna'@'%' identified by 'somepassword';
Query OK, 0 rows affected (0.01 sec)

mysql> grant all privileges on *.* to 'tuna'@'%';
Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.03 sec)

When I show grants for 'tuna'@'%', I can see and do what I expect.

Appreciate any clarification on what I did wrong on the RDS MySQL instance.