2020/10/27

I've got a bit of a double-bind situation here...

• Email retrieval on cloud5 (where it had been for some months) stopped working when I upgraded Ubuntu to 20.04. Dovecot gives errors on IMAP and POP3. Postfix (SMTP) is still working, and we are able to access email via Roundcube, but not desktop or mobile clients.
• Meanwhile, Dovecot on the new cloud1 server is working -- but MySQL refuses to accept connections from MySQL Workbench, making it difficult to set up databases, which makes it difficult (though not impossible) to set up Roundcube there.

I'm focusing on fixing the MySQL issue, as that is a blocker on several issues.

One symptom: MySQL on cloud5 (which works properly) will only let me connect via CLI if I have a username and password. MySQL on cloud1 (not working for ssh tunnel connections) will let me connect from CLI with or without a username and with or without a password.

After looking extensively at configuration files, one relevant difference seems to be the GRANTS (SHOW GRANTS FOR 'root'@'localhost';):

cloud1 (kind of not working)

Grants for root@localhost

GRANT ALL PRIVILEGES ON *.* TO `root`@`localhost` IDENTIFIED VIA mysql_native_password USING 'invalid' OR unix_socket WITH GRANT OPTION GRANT PROXY ON ''@'%' TO 'root'@'localhost' WITH GRANT OPTION

2 rows in set (0.000 sec)

cloud5 (working properly)

Grants for root@localhost

GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE, CREATE ROLE, DROP ROLE ON *.* TO `root`@`localhost` WITH GRANT OPTION GRANT APPLICATION_PASSWORD_ADMIN, AUDIT_ADMIN,BACKUP_ADMIN, BINLOG_ADMIN, BINLOG_ENCRYPTION_ADMIN, CLONE_ADMIN, CONNECTION_ADMIN, ENCRYPTION_KEY_ADMIN, GROUP_REPLICATION_ADMIN, INNODB_REDO_LOG_ARCHIVE, INNODB_REDO_LOG_ENABLE, PERSIST_RO_VARIABLES_ADMIN, REPLICATION_APPLIER, REPLICATION_SLAVE_ADMIN, RESOURCE_GROUP_ADMIN, RESOURCE_GROUP_USER, ROLE_ADMIN, SERVICE_CONNECTION_ADMIN, SESSION_VARIABLES_ADMIN, SET_USER_ID, SHOW_ROUTINE, SYSTEM_USER, SYSTEM_VARIABLES_ADMIN, TABLE_ENCRYPTION_ADMIN, XA_RECOVER_ADMIN ON *.* TO `root`@`localhost` WITH GRANT OPTION GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION

3 rows in set (0.00 sec)

Trying to apply the cloud5 settings to cloud1, I get this for the first GRANT query:

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'ROLE, DROP ROLE ON *.* TO `root`@`localhost` WITH GRANT OPTION' at line 1

Sooo... let's take a closer look at what the cloud1 setup does.

GRANT ALL PRIVILEGES ON *.*	this user is God
TO `root`@`localhost`	only if connected locally
IDENTIFIED VIA mysql_native_password	mysql_native_password plugin
USING 'invalid' OR unix_socket	"invalid" is maybe like saying FALSE -- it won't ever work? ...leaving unix_socket as the only viable option
WITH GRANT OPTION	allow user to create other users with same privileges

Let's try

GRANT ALL PRIVILEGES ON *.*
  TO `root`@`localhost`
  IDENTIFIED VIA ed25519
  USING PASSWORD('password_here') OR unix_socket
  WITH GRANT OPTION

That gives me

ERROR 1524 (HY000): Plugin 'ed25519' is not loaded

INSTALL SONAME 'auth_ed25519';

Query OK, 0 rows affected (0.002 sec)

Trying the GRANT again...

Query OK, 0 rows affected (0.001 sec)

Now when I try to connect with Workbench, I get a much quicker error about not being able to load the ed25519 plugin. Okay, so we need to make that automatic...

Unfortunately, the client_ed25519 plugin seems to be separate from auth_ed25519? this page suggested a package to install in order to get the client library, and I did, but it still didn't work. This post suggests that the problem has been fixed, but... kinda no.

For now, then, let's try the default plugin, if there is one.

GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY '[password]' WITH GRANT OPTION;

This finally worked.