Criar banco de dados mysql e usuário no script bash

Isto é o que eu uso:https://raw.githubusercontent .com/saadismail/useful-bash-scripts/master/db.sh

No seu caso, você pode usar isso:

# create random password
PASSWDDB="$(openssl rand -base64 12)"

# replace "-" with "_" for database username
MAINDB=${USER_NAME//[^a-zA-Z0-9]/_}

# If /root/.my.cnf exists then it won't ask for root password
if [ -f /root/.my.cnf ]; then

    mysql -e "CREATE DATABASE ${MAINDB} /*\!40100 DEFAULT CHARACTER SET utf8 */;"
    mysql -e "CREATE USER ${MAINDB}@localhost IDENTIFIED BY '${PASSWDDB}';"
    mysql -e "GRANT ALL PRIVILEGES ON ${MAINDB}.* TO '${MAINDB}'@'localhost';"
    mysql -e "FLUSH PRIVILEGES;"

# If /root/.my.cnf doesn't exist then it'll ask for root password   
else
    echo "Please enter root user MySQL password!"
    echo "Note: password will be hidden when typing"
    read -sp rootpasswd
    mysql -uroot -p${rootpasswd} -e "CREATE DATABASE ${MAINDB} /*\!40100 DEFAULT CHARACTER SET utf8 */;"
    mysql -uroot -p${rootpasswd} -e "CREATE USER ${MAINDB}@localhost IDENTIFIED BY '${PASSWDDB}';"
    mysql -uroot -p${rootpasswd} -e "GRANT ALL PRIVILEGES ON ${MAINDB}.* TO '${MAINDB}'@'localhost';"
    mysql -uroot -p${rootpasswd} -e "FLUSH PRIVILEGES;"
fi