(It\'s probably a dumb question due to my limited knowledge with Docker or mysql administration, but since I spent a whole evening on this issue, I dare to ask it.)
For conversion,you can create ~/.my.cnf file in host:
~/.my.cnf
[Mysql] user=root password=yourpass host=127.0.0.1 port=3306
Then next time just run mysql for mysql client to open connection.
mysql