The Dockerfile creates a container with MySQL-Server installed.

• access is allowed from any host for the mysql user.
• a password for the MySQL root user (which can only be used to connect from inside the container) is set (default rootpw, configurable in Dockerfile)
• a new MySQL user is created (default username mysql, configurable in Dockerfile)
• anonymous user and test databases are removed

Mount a directory from the host to /var/lib/mysql (or, if you changed the DATADIR in Dockerfile, to the DATADIR path) to make the databases persistent:

docker run -v="$HOME/db":"/var/lib/mysql" -d -name mysql <image-id>

The directory is initialized by the start-script on every run if no database is already present.

Note that you can only connect with the mysql user from outside the container, not with the root user.