I agree someone may have done it, and packaging scripts will need to account for this, however I've never seen or found a stack overflow, dba.stackexchange.com, blog or any other reference to it. I tried searching Google for CREATE USER mysql and haven't found an exact match . All examples I've seen focus on a personal name (dan), a role (admin), root. or and application name.

Okay. I'll try this — two all-privilege accounts, authenticated with unix_socket. One is root. The other is:

  # Use $auth_root_socket_user if explicitly specified.

  # Otherwise use the owner of datadir - ${user:-$USER}

  # Use 'root' as a fallback

  auth_root_socket_user=${auth_root_socket_user:-${user:-${USER:-root}}}

The logic here is — both root user and the owner of the datadir do not need to know the password, they have the full access to the data anyway. So we don't ask them to provide the password.

This covers both your mysql@localhost suggestion and debian bug#848616 (installed locally under a normal user) use cases.

Nice work serg. Always great to see large chunks of packaging script disappear (https://github.com/mariadb/server/commit/25c6d626570e048fc8ddf1ef500a0c601d8b8a60). Trivial, minor, and not without RPM implications, does `./support-files/mysql-log-rotate.sh` need a `su mysql mysql`?

No, I don't think so. That's the same with Debian — if a script can read /etc/mysql/debian.cnf then it's run as root and that alone is enough. In mysql-log-rotate.sh it looks like it needs to read ~root/.my.cnf, so it's enough too.

By the way, with mysql user it's somewhat tricky. I didn't dig too deep but the only sudo that I managed to get working was

$ sudo sudo -umysql mysql -umysql

which looks a bit redundant to me. For running as root simple sudo mysql works.

Great to see this finally done upstream! A big thank you serg for taking the time to merge it in.