Force own MySQL Root

let-mysql-know-the-boss.sql

SET @@SESSION.SQL_LOG_BIN=0;
DELETE FROM mysql.user WHERE Host = '';
DELETE FROM mysql.user WHERE User = 'root';
DELETE FROM mysql.user WHERE User = '$MYSQL_USER';
CREATE OR REPLACE USER 'root'@'%' IDENTIFIED BY '$MYSQL_ROOT_PASS';
GRANT ALL ON *.* TO 'root'@'%' WITH GRANT OPTION;
DROP DATABASE IF EXISTS test;

CREATE DATABASE IF NOT EXISTS $MYSQL_DB;
CREATE OR REPLACE USER '$MYSQL_USER'@'%' IDENTIFIED BY '$MYSQL_PASS';
GRANT ALL ON $MYSQL_DB.* TO '$MYSQL_USER'@'%';
FLUSH PRIVILEGES;