Remove MySQL root password

Environment

1. Operation System: Ubuntu 18.04.3 LTS
2. MySQL Server: 5.7.28

Use on your own risk !

$ sudo service mysql stop
$ sudo rm -rf /var/lib/mysql
$ sudo rm -rf /var/run/mysqld
$ sudo mkdir /var/run/mysqld
$ sudo chown -R mysql:mysql /var/run/mysqld
$ sudo /usr/lib/mysqld_safe --user=mysql --initialize-insecure
$ sudo service mysql start