Web Kiosk CentOS 7

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Purpose

Powers that be wanted a TV mounted in a lobby, with content playing on it for visitors to ignore. At first I was told to install a flash drive and play images with the flush mount TV. Instead I thought it would be a good idea to have a NUC installed behind the TV running a web browser in full screen mode, displaying a WordPress site that my boss could manage (He really likes wordpress).

Hardware

Intel BOXNUC6CAYH
-2GB DDR3 RAM (I had laying around, should be enough to display a single web page and run the background tasks)
-Intel(R) Celeron(R) CPU J3455 @ 1.50GHz (Came with the NUC. Just enough to display a web page and run WordPress)
-KingDian S100 16GB SSD (This was dirt cheap, and will probably die with the lack of RAM installed.)

This is connected to the wifi since there is no ethernet installed behind the TV. But since the site is on the unit I can live with broken connections. A simple script later on should take care of this.

Setup

Packages

A fresh install of CentOS 7, and the usual basics. Please note the following

  • x11 server did not install with the group install of Xfce, so it was installed seperately.
  • [1]Keyboard and mouse did not work out the box, and I had to install the evdev drivers. Granted no one should be using a keyboard and mouse with this system, but I will be running VNC as an extra method for managing the system (Windows weenies will be asking fewer questions this way.)
yum -y update
yum -y install epel-release
yum makecache
yum -y install htop nano xorg-x11-server-Xorg smartmontools chromium xorg-x11-drv-evdev wget httpd mysql php mariadb-server php-mysql
yum -y group install Xfce
  • Install unclutter[2][3], this is useful for getting rid of the mouse pointer when not in use.
  • NOTE: I ran into issues downloading from archlinux, quick and dirty google search had me run across a git repo.[4]
  • Repo method:
yum install -y git libev-devel libX11-devel
yum groupinstall "Development Tools"
git clone https://github.com/Airblader/unclutter-xfixes && cd unclutter-xfixes
make
make install
  • Arch method:
wget -O unclutter.tar https://www.archlinux.org/packages/community/x86_64/unclutter/download/
tar -xf unclutter.tar
mv usr/bin/unclutter /usr/bin/unclutter
rm -rf usr
  • Start the services and prep for config
systemctl enable httpd
systemctl enable mariadb
systemctl start httpd
systemctl start mariadb
mysql -e "UPDATE mysql.user SET Password=PASSWORD('password') WHERE User='root';"
mysql -e "DELETE FROM mysql.user WHERE User='root' AND Host NOT IN ('localhost', '127.0.0.1', '::1');"
mysql -e "DELETE FROM mysql.user WHERE User='';"
mysql -e "DROP DATABASE test;"
mysql -e "create database wordpress;"
mysql -e "grant all privileges on wordpress.* to 'wordpress'@'%' identified by 'password';"
mysql -e "FLUSH PRIVILEGES;"
  • Loosen SELinux. Normall you don't do this, but for something as simple as this I am ok with it.
setsebool -P httpd_unified 1

TTY1 Autologin

Now create the auto-login process.

useradd publicuser
rm /etc/systemd/system/getty.target.wants/getty@tty1.service
cp /lib/systemd/system/getty@.service /etc/systemd/system/getty@tty1.service
sed -i -e "s/\/sbin\/agetty/\0 --autologin publicuser/" /etc/systemd/system/getty@tty1.service
ln -s /etc/systemd/system/getty@tty1.service /etc/systemd/system/getty.target.wants/getty@tty1.service

cat << EOF >>/home/publicuser/.bash_profile
if [[ -z \$DISPLAY ]] && [[ \$(tty) = /dev/tty1 ]]; then # Check if we have a display and we're on TTY1
startx
else
echo "Please contact the help desk and provide the following"
echo "IP : "
echo "Hostname : $hostname"
fi
EOF

cat << EOF>>/hom/publicuser/.xinitrc
exec startxfce4
EOF

reboot

After the reboot, you should see the desktop start up. If it does not troubleshoot.

Configure Chromium Auto-start

  • Make sure to have DNS entries for your site. I am using hosts entries on the computer since it is remote and will not have access to DNS, but will create a DNS entry for management purposes.

[5][6]

cat << EOF>>/etc/xdg/autostart/kiosk.desktop
[Desktop Entry]
Encoding=UTF-8
Name=Kiosk
GenericName=program
Comment=LobbyKiosk
Exec=chromium-browser --noerrdialogs --kiosk http://siteurl.tld
Icon=/usr/share/pixmaps/program.jpg
Terminal=false
Type=Application
Categories=
OnlyShowIn=XFCE;
EOF

Configure Power Settings and Disable Mouse Pointer

We want to prevent the system from going to sleep, blanking the screen, loading the screen saver[7], or showing the pointer on the screen.
One issue I am having is understanding the best method for exporting the display. I am too used to working in bash and not with a gui. The following export does not work, but the display settings appear to still work.
Initially the xset commands were getting ignored by xfce power management. In order to get around this I had to use xfconf-query[8] to make things stick

  • Create the script
cat << EOF>>/home/publicuser/power.sh
#!/bin/sh
sleep 10
export DISPLAY=$(who | grep -E "publicuser pts\/[0-9]" | grep -Eo "\(:[0-9][.]?[0-9]?\)" | sed 's/(//; s/)//')
xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/dpms-enabled -s false
/usr/bin/unclutter -grab
EOF

chmod +x /home/publicuser/power.sh
sed -i 's/<\/property>/\ \ <property\ name=\"blank-on-ac\"\ type=\"int\"\ value=\"0\"\/>\n&/g' /home/publicuser/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-power-manager.xml
  • Create the auto-launch of the script.
cat << EOF>>/etc/xdg/autostart/power.desktop
[Desktop Entry]
Encoding=UTF-8
Name=powersettings
GenericName=program3
Comment=DisablePower
Exec=/home/publicuser/power.sh
Icon=/usr/share/pixmaps/program.jpg
Terminal=false
Type=Application
Categories=
OnlyShowIn=XFCE;

Setup WordPess

But first I download and extract the files needed over ssh.

wget https://wordpress.org/latest.zip
unzip latest.zip
mv wordpress /var/www/html/
find /var/www/html/wordpress/ -type d -exec chmod 755 {} \;
find /var/www/html/wordpress/ -type f -exec chmod 644 {} \;
mkdir /var/www/html/wordpress/logs
chown -R apache:apache /var/www/html/wordpress

  • Setup a vhost to load the site.
cat << EOF >>/etc/httpd/conf.d/vhost.conf
<VirtualHost *:80>
ServerName localhost
DocumentRoot "/var/www/html/wordpress"
</VirtualHost>
EOF
  • Up until now I have been setting this up remotely, however I will now need to start using the ol' keyboard and mouse so I can configure using localhost. Follow the standard wordpress setup[9].
  • https://bbs.archlinux.org/viewtopic.php?id=225780
  • https://www.archlinux.org/packages/community/x86_64/unclutter/
  • https://stackoverflow.com/questions/660613/how-do-you-hide-the-mouse-pointer-under-linux-x11
  • https://ostechnix.com/auto-hide-mouse-pointer-using-unclutter-after-a-certain-time/#:~:text=Auto%20Hide%20Mouse%20Pointer%20Using%20Unclutter%20After%20A%20Certain%20Time%20In%20Linux&text=If%20the%20mouse%20cursor%20has,after%205%20seconds%20by%20default.
  • https://www.danpurdy.co.uk/web-development/raspberry-pi-kiosk-screen-tutorial/
  • https://superuser.com/questions/461035/disable-google-chrome-session-restore-functionality
  • https://superuser.com/questions/644804/disable-screensaver-screen-blank-via-command-line
  • https://askubuntu.com/questions/407287/change-xfce4-power-manager-option-from-terminal
  • https://codex.wordpress.org/Installing_WordPress#Famous_5-Minute_Installation