Installing MySQL 8 in silent mode on Ubuntu ( Without prompting )

install_mysql8_silent.sh

#update and install some dependencies 
sudo apt-get update && apt-get upgrade -y;
sudo apt-get install -y debconf-utils zsh htop libaio1;

#set the root password
DEFAULTPASS="rootpass"

#set some config to avoid prompting
sudo debconf-set-selections <<EOF
mysql-apt-config mysql-apt-config/select-server select mysql-8.0
mysql-community-server mysql-community-server/root-pass password $DEFAULTPASS
mysql-community-server mysql-community-server/re-root-pass password $DEFAULTPASS
EOF

#get the mysql repository via wget
wget --user-agent="Mozilla" -O /tmp/mysql-apt-config_0.8.10-1_all.deb https://dev.mysql.com/get/mysql-apt-config_0.8.10-1_all.deb;

#set debian frontend to not prompt
export DEBIAN_FRONTEND="noninteractive";

#config the package
sudo -E dpkg -i /tmp/mysql-apt-config_0.8.10-1_all.deb;

#update apt to get mysql repository
sudo apt-get update

#install mysql according to previous config
sudo -E apt-get install mysql-server mysql-client --assume-yes --force-yes

So I got this working for MySql version 8.0.32.

mysql-apt-config mysql-apt-config/select-tools select Enabled
mysql-apt-config mysql-apt-config/unsupported-platform select abort
mysql-apt-config mysql-apt-config/preview-component string
mysql-apt-config mysql-apt-config/repo-url string http://repo.mysql.com/apt
mysql-apt-config mysql-apt-config/select-server select
mysql-apt-config mysql-apt-config/repo-codename select bionic
mysql-apt-config mysql-apt-config/select-preview select Disabled
mysql-apt-config mysql-apt-config/tools-component string mysql-tools
mysql-apt-config mysql-apt-config/select-product select
mysql-apt-config mysql-apt-config/repo-distro select ubuntu
mysql-apt-config mysql-apt-config/dmr-warning note
EOF

wget -c https://dev.mysql.com/get/mysql-apt-config_0.8.24-1_all.deb
sudo DEBIAN_FRONTEND="noninteractive" dpkg -i mysql-apt-config_0.8.24-1_all.deb
gpg --batch --keyserver hkps://keys.openpgp.org --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4;
sudo apt update
sudo DEBIAN_FRONTEND="noninteractive" apt install -y mysql-server 

The trick for me was to run the mysql-apt-config_0.8.24-1_all.deb in interactive mode. Then run the tool debconf-get-selections | grep mysql-apt-config. That will give you the contents of the EOF block

You need to run sudo apt install debconf-utils to get the debconf-get-selections command.