최초 설치후
- you can confirm root password is empty from error log
$ grep password /var/log/mysql/error.log
- connect mysql as a root user and initialize
$ sudo mysql -uroot mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password; Query OK, 0 rows affected (0.00 sec)
- set password
$ mysqladmin --user=root password