Ha. Mostly because I couldn't even get the headless docker to write to the database either.
1) My ip for unraid is 192.168.2.25. It's a static ip.
2) I used the commands I used are as follows:
docker exec -it MariaDB bash
Then I used mysql -u root (since theres no root password for the docker)
This gives me an error for TERM so I then use 'export TERM=xterm' (This allows me to issue the commands)
CREATE USER 'xbmc' IDENTIFIED BY 'xbmc'; and I hit return (I'm still on Gotham, so I'm sticking with xbmc,xbmc for now)
GRANT ALL ON *.* TO 'xbmc'; and I hit return
Then I exit with \q.
3) I don't have any other containers using the mariadb container. I wish I did so I would know if its a prob with openelec and not docker or vice versa, but yeah.
I'd love a walkthrough if it's not too much trouble. Like I mentioned before I had a shared mysql database working on a windows machine, but moving to docker has been a no go so far for me.