Ubuntu Server 20.04 LTS Firefox kiosk

remove.sh

# Stop the kiosk service
sudo systemctl stop kiosk

# Remove the kiosk service from startup
sudo systemctl disable kiosk

# Remove the kiosk service
sudo rm -f /etc/systemd/system/kiosk.service

# Reload systemctl daemons
sudo systemctl daemon-reload

# Remove the kiosk startup file and directory
sudo rm -rf /opt/kiosk

# Remove X.org, OpenBox, Firefox and autoremove associated programs no longer in use
sudo apt remove --autoremove -y xorg openbox firefox

setup.sh

# Install X.org, OpenBox, Firefox
sudo apt install --no-install-recommends -y xorg openbox firefox

# Write X.org startup script to /opt/kiosk/kiosk.sh
sudo mkdir /opt/kiosk
echo "xset s
xset -dpms
off openbox-session &
while true;
do
  /usr/bin/firefox --kiosk --private-window 'https://honbra.com/'
done" | sudo tee /opt/kiosk/kiosk.sh

# Write service file to /etc/systemd/system/kiosk.service
echo "[Unit]
Description=Start kiosk
[Service]
Type=simple
ExecStart=sudo startx /etc/X11/Xsession /opt/kiosk/kiosk.sh
[Install]
WantedBy=multi-user.target" | sudo tee /etc/systemd/system/kiosk.service

# Add permissions to the files
sudo chmod 644 /etc/systemd/system/kiosk.service
sudo chmod +x /opt/kiosk/kiosk.sh

# Enable the service on startup
sudo systemctl daemon-reload
sudo systemctl enable kiosk

# Finish
echo "Edit /etc/systemd/system/kiosk.service to change the website.
Run 'sudo systemctl start kiosk' to start the kiosk
Thanks for using the Kiosk gist by @HonbraDev :)"

Only issue I'm facing is the display is not fullscreen, how can I set its resolution? Thanks

You should edit /opt/kiosk/kiosk.sh and add resolution parameters before --private-window. For example if you have 1920x1080 you should have string like this:

/usr/bin/firefox --kiosk --height 1080 --width 1920 --private-window 'https://honbra.com/'