root@deepin-PC:/opt/mysql_docker# docker ps 
CONTAINER ID    IMAGE        COMMAND         CREATED       STATUS       PORTS                NAMES
1f9aa5b79b6a    mysql:latest    "docker-entrypoint.s…"  About a minute ago  Up 59 seconds    0.0.0.0:3306->3306/tcp, 33060/tcp  mysql

mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select host,user from user;
+-----------+------------------+
| host   | user       |
+-----------+------------------+
| %     | root       |
| localhost | mysql.infoschema |
| localhost | mysql.session  |
| localhost | mysql.sys    |
| localhost | root       |
+-----------+------------------+
5 rows in set (0.00 sec)

mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';
Query OK, 0 rows affected (0.02 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

root@deepin-PC:/opt/mysql_docker# docker ps -a
CONTAINER ID    IMAGE        COMMAND         CREATED       STATUS       PORTS                NAMES
1f9aa5b79b6a    mysql:latest    "docker-entrypoint.s…"  6 minutes ago    Up 6 minutes    0.0.0.0:3306->3306/tcp, 33060/tcp  mysql
root@deepin-PC:/opt/mysql_docker# docker logs -f --tail 10 1f9aa5b79b6a
2020-05-11 14:14:30+00:00 [Note] [Entrypoint]: MySQL init process done. Ready for start up.

2020-05-11T14:14:30.702850Z 0 [Warning] [MY-011070] [Server] 'Disabling symbolic links using --skip-symbolic-links (or equivalent) is the default. Consider not using this option as it' is deprecated and will be removed in a future release.
2020-05-11T14:14:30.702952Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.20) starting as process 1
2020-05-11T14:14:30.712787Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2020-05-11T14:14:31.064937Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2020-05-11T14:14:31.191792Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: '/var/run/mysqld/mysqlx.sock' bind-address: '::' port: 33060
2020-05-11T14:14:31.284386Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2020-05-11T14:14:31.292565Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2020-05-11T14:14:31.312549Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.20' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server - GPL.