This is a CentOS8 version for MySQL8

mysql_secure.sh

#!/bin/bash

#
# Automate mysql secure installation for Redhat/CentOS systems
#
#  - You can set a password for root accounts.
#  - You can remove root accounts that are accessible from outside the local host.
#  - You can remove anonymous-user accounts.
#  - You can remove the test database (which by default can be accessed by all users, even anonymous users),
#    and privileges that permit anyone to access databases with names that start with test_.
#  For details see documentation: http://dev.mysql.com/doc/refman/8.0/en/mysql-secure-installation.html
#
# Tested on CentOS 8.1
#
# Usage:
#  Setup mysql root password:  ./mysql_secure.sh 'your_new_root_password'
#  Change mysql root password: ./mysql_secure.sh 'your_old_root_password' 'your_new_root_password'"
#

# Delete package expect when script is done
# 0 - No;
# 1 - Yes.
PURGE_EXPECT_WHEN_DONE=0
NEW_MYSQL_PASSWORD="Change it to your own password, it must be strong enough, such as !@#$%^&^*&234567nnll"

#
# Check the bash shell script is being run by root
#
if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root" 1>&2
   exit 1
fi

#
# Check is expect package installed
#
if ! rpm -q "expect"; then
    echo "Can't find expect. Trying install it..."
    dnf -y install expect
fi

SECURE_MYSQL=$(expect -c "

set timeout 3
spawn mysql_secure_installation

expect \"Would you like to setup VALIDATE PASSWORD component?\"
send \"y\r\"

expect \"Please enter 0 = LOW, 1 = MEDIUM and 2 = STRONG:\"
send \"2\r\"

expect \"New password:\"
send \"$NEW_MYSQL_PASSWORD\r\"

expect \"Re-enter new password:\"
send \"$NEW_MYSQL_PASSWORD\r\"

expect \"Do you wish to continue with the password provided?\"
send \"y\r\"

expect \"Remove anonymous users?\"
send \"y\r\"

expect \"Disallow root login remotely?\"
send \"y\r\"

expect \"Remove test database and access to it?\"
send \"y\r\"

expect \"Reload privilege tables now?\"
send \"y\r\"

expect eof
")

#
# Execution mysql_secure_installation
#
echo "${SECURE_MYSQL}"

if [ "${PURGE_EXPECT_WHEN_DONE}" -eq 1 ]; then
    # Uninstalling expect package
    dnf -y remove expect
fi

exit 0