Autostart Chromium på Kiosk

Source: Download script

Last Updated: 4. December 2024 by Agnete Moos (agms@sonderborg.dk)

Parameters:

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Click to see the source code

#!/bin/bash

# Make Chromium autostart, fx. in preparation for OS2Display.

# Policies:
# AutofillAddressEnabled: Disable Autofill of addresses
# AutofillCreditCardEnabled: Disable Autofill of payment methods
# AutoplayAllowed: Allow auto-playing content. Relevant for displaying videos without user input?
# PasswordManagerEnabled: Disables the password manager, which should also prevent autofilling passwords
# TranslateEnabled: Don't translate or prompt for translation of content that isn't in the current locale on a computer that's often userless
#
# Launch args:
# Note: Convert these to policies if it is or becomes possible!
# --enable-offline-auto-reload: This should reload all pages if the browser lost internet access and regained it
# --password-store=basic: Don't prompt user to unlock GNOME keyring on a computer that's often userless

set -ex

# Separates the programmatic value from the text description
get_value_from_option() {
  echo "$1" | cut --delimiter ":" --fields 1
}

TIME=$1
URL=$2
WIDTH=$3
HEIGHT=$4
ORIENTATION=$5
LOCK_DOWN_KEYBINDS=$(get_value_from_option "$6")  # 0: No binds removed, 1: Most binds removed, 2: All binds removed (specifically most + binds for printing, reloading and changing zoom)

CUSER="chrome"
XINITRC="/home/$CUSER/.xinitrc"
BSPWM_CONFIG="/home/$CUSER/.config/bspwm/bspwmrc"
CHROMIUM_SCRIPT='/usr/share/os2borgerpc/bin/start_chromium.sh'
ROTATE_SCREEN_SCRIPT_PATH="/usr/share/os2borgerpc/bin/rotate_screen.sh"
OLD_ROTATE_SCREEN_SCRIPT_PATH="/usr/local/bin/rotate_screen.sh"
ENVIRONMENT_FILE="/etc/environment"
AUTOLOGIN_SCRIPT="/usr/share/os2borgerpc/bin/autologin.sh"
AUTOLOGIN_COUNTER="/etc/os2borgerpc/login_counter.txt"
COUNTER_RESET_SERVICE="/etc/systemd/system/reset_login_counter.service"
REBOOT_SCRIPT="/usr/share/os2borgerpc/bin/chromium_error_reboot.sh"
MAXIMUM_CONSECUTIVE_AUTOLOGINS=3
# We use xbindkeys to disable some keyboard shortcuts in case people connect a keyboard to their Kiosk computer.
XBINDKEYS_CONFIG=/home/$CUSER/.xbindkeysrc

if ! get_os2borgerpc_config os2_product | grep --quiet kiosk; then
  echo "Dette script er ikke designet til at blive anvendt på en regulær OS2borgerPC-maskine."
  exit 1
fi

# Create user.
# TODO: This is now built into the image instead, but for now it's kept here for backwards compatibility with old images
# Remove this after 2025-04, when 20.04 is out of support.
# useradd will fail on multiple runs, so prevent that
if ! id $CUSER > /dev/null 2>&1; then
  useradd $CUSER --create-home --password 12345 --shell /bin/bash --user-group --comment "Chrome"
fi

# Autologin default user
mkdir --parents /etc/systemd/system/getty@tty1.service.d

# Note: The empty ExecStart is not insignificant!
# By default the value is appended, so the empty line changes it to an override
# We make agetty use our own login-program instead of /bin/login
# so we can customize the behavior
cat << EOF > /etc/systemd/system/getty@tty1.service.d/override.conf
[Service]
ExecStart=
ExecStart=-/sbin/agetty --noissue --login-program $AUTOLOGIN_SCRIPT --autologin $CUSER %I $TERM
Type=idle
EOF

# Create the autologin script

# Ensure that the folder exists
mkdir --parents "$(dirname $AUTOLOGIN_SCRIPT)"

cat << EOF > $AUTOLOGIN_SCRIPT
#! /usr/bin/env bash
COUNTER=\$(cat $AUTOLOGIN_COUNTER)
COUNTER=\$((COUNTER+1))
echo \$COUNTER > $AUTOLOGIN_COUNTER
if [ \$COUNTER -le $MAXIMUM_CONSECUTIVE_AUTOLOGINS ]; then
  if [ \$COUNTER -gt 1 ]; then
    # Sleep before autologin attempts other than the first
    sleep 10
  fi
  # Autologin as $CUSER
  /bin/login -f $CUSER
else
  # Regular login prompt
  /bin/login
fi
EOF

# To maintain the functionality of the error reboot script
if [ -f "$REBOOT_SCRIPT" ]; then
  sed --in-place --expression "\@else@{ n; n; s@/bin/login@$REBOOT_SCRIPT@ }" \
      --expression "s/Regular login prompt/Reboot the computer/" $AUTOLOGIN_SCRIPT
fi

chmod 700 $AUTOLOGIN_SCRIPT

# Create login counter
echo "0" > $AUTOLOGIN_COUNTER

# Create service to reset counter when
# the computer is booted
cat << EOF > $COUNTER_RESET_SERVICE
[Unit]
Description=Reset the autologin counter when the computer starts

[Service]
Type=oneshot
ExecStart=sh -c 'echo "0" > $AUTOLOGIN_COUNTER'

[Install]
WantedBy=multi-user.target
EOF

systemctl enable --now "$(basename $COUNTER_RESET_SERVICE)"

# Create script to rotate screen

# ...remove the rotate script from its previous location
rm --force $OLD_ROTATE_SCREEN_SCRIPT_PATH

cat << EOF > $ROTATE_SCREEN_SCRIPT_PATH
#!/usr/bin/env sh

set -x

TIME=\$1
ORIENTATION=\$2

sleep \$TIME

export XAUTHORITY=/home/$CUSER/.Xauthority

# --listactivemonitors lists the primary monitor first
ALL_MONITORS=\$(xrandr --listactivemonitors | tail -n +2 | cut --delimiter ' ' --fields 6)

# Make all connected monitors display what the first monitor displays, rather than them extending the desktop
PRIMARY_MONITOR=\$(echo "\$ALL_MONITORS" | head -n 1)
OTHER_MONITORS=\$(echo "\$ALL_MONITORS" | tail -n +2)
echo "\$OTHER_MONITORS" | xargs -I {} xrandr --output {} --same-as "\$PRIMARY_MONITOR"

# Rotate screen - and if more than one monitor, rotate them all.
echo "\$ALL_MONITORS" | xargs -I {} xrandr --output {} --rotate \$ORIENTATION
EOF

chmod +x $ROTATE_SCREEN_SCRIPT_PATH


# Kiosk mode cannot currently be set via policy
# so we set the value in the environment file
# To prevent overwriting changes made by other scripts
# we only set the value if it does not exist
if ! grep --quiet "BPC_KIOSK" $ENVIRONMENT_FILE; then
  echo 'BPC_KIOSK="--kiosk"' >> $ENVIRONMENT_FILE
fi

# Create a script dedicated to launch chromium, which both xinit or any wm
# launches, to avoid logic duplication, fx. having to update chromium settings
# in multiple files
# If this script's path/name is changed, remember to change it in
# wm_keyboard_install.sh as well
mkdir --parents "$(dirname "$CHROMIUM_SCRIPT")"

# TODO: Make URL a policy instead ("RestoreOnStarupURLs", see chrome_install.sh)
# password-store=basic and enable-offline-auto-reload do not exist as policies so we add them as flags.
cat << EOF > "$CHROMIUM_SCRIPT"
#!/bin/sh

DIMENSIONS=\$(xrandr | grep '*' | awk '{print \$1}')

WM=\$1
IURL="$URL"

# Check if WIDTH is provided; if not, fall back to default from xrandr
if [ "$WIDTH" = "auto" ]; then
    IWIDTH="\$(echo \$DIMENSIONS | cut -d'x' -f1)"
else
    IWIDTH="$WIDTH"
fi

# Check if HEIGHT is provided; if not, fall back to default from xrandr
if [ "$HEIGHT" = "auto" ]; then
    IHEIGHT="\$(echo \$DIMENSIONS | cut -d'x' -f2)"
else
    IHEIGHT="$HEIGHT"
fi

COMMON_SETTINGS="--password-store=basic --enable-offline-auto-reload"


if [ "$WIDTH" = "auto" ] || [ "$HEIGHT" = "auto" ]; then
  if [ "$ORIENTATION" = "left" ] || [ "$ORIENTATION" = "right" ] ; then
    TEMP=\$IWIDTH
    IWIDTH=\$IHEIGHT
    IHEIGHT=\$TEMP
  fi
fi


if [ "\$WM" == "wm" ]; then
  chromium-browser "\$BPC_KIOSK" "\$IURL" "\$COMMON_SETTINGS"
else
  exec chromium-browser "\$BPC_KIOSK" "\$IURL" --window-size="\$IWIDTH,\$IHEIGHT" --window-position=0,0 "\$COMMON_SETTINGS"
fi
EOF
chmod +x "$CHROMIUM_SCRIPT"

if [ "$LOCK_DOWN_KEYBINDS" -lt "1" ]; then
  rm --force $XBINDKEYS_CONFIG
else
  XBINDKEYS_MAYBE='xbindkeys &'
  # Attempt at preventing everything except reload, print and zoom
  cat << EOF > $XBINDKEYS_CONFIG
# Prevent saving the page
""
  control + s

# Prevent closing tabs/windows/the browser
""
  control + w
""
  control + shift + w

# Prevent opening new tabs
""
  control + t
""
  control + shift + t

# Prevent opening new windows
""
  control + n
""
  control + shift + n

# Prevent opening the tab selection window
""
  control + shift + a

# Prevent bookmarking
""
  control + d
""
  control + shift + d
""
  control + shift + o

# Prevent opening a file from disk
""
  control + o

# Prevent opening history
""
  control + h

# Prevent opening download history
""
  control + j

# Prevent closing the browser, f has to be uppercase for it to work
""
  alt + F4

# Prevent selecting all text
""
  control + 7
EOF
  # Additionally prevent print, reload and zoom
  if [ "$LOCK_DOWN_KEYBINDS" -gt "1" ]; then
  cat << EOF >> $XBINDKEYS_CONFIG
# Additionally prevent reloading, printing and changing zoom

# Prevent reloading
""
  control + r

# Prevent printing
""
  control + p

# Prevent changing zoom
""
  control + 0
""
  control + shift + 0
""
  control + plus
""
  control + shift + plus
""
  control + minus
""
  control + shift + minus
""
  control + KP_Add
""
  control + KP_Subtract
EOF
  fi
fi

# Launch chromium upon starting up X
cat << EOF > $XINITRC
#!/bin/sh

xset s off
xset s noblank
xset -dpms

$ROTATE_SCREEN_SCRIPT_PATH $TIME $ORIENTATION

$XBINDKEYS_MAYBE

# Launch chromium with its non-WM settings
exec $CHROMIUM_SCRIPT nowm
EOF

# If bspwm config (for the onscreen keyboard) is found, restore starting it up instead of starting chromium directly
if [ -f $BSPWM_CONFIG ]; then
# Don't auto-start chromium from xinitrc
  sed -i "s,\(.*$CHROMIUM_SCRIPT.*\),#\1," $XINITRC

  # Instead autostart bspwm
	cat <<- EOF >> $XINITRC
		exec bspwm
	EOF
fi

# Start X upon login
PROFILE="/home/$CUSER/.profile"
if ! grep --quiet -- 'exit' $PROFILE; then # Ensure idempotency
  # This first line cleans up after previous versions of the script
  sed --in-place --expression "/startx/d" --expression "/for i in/d" --expression "/sleep/d" \
      --expression "/done/d" --expression "/chromium_error_reboot/d" $PROFILE
  cat << EOF >> $PROFILE
startx
exit
EOF
fi

Beskrivelse

Start Chromium i kiosk-mode og sæt startside URLen.

Dette script forudsætter at følgendes scripts allerede er kørt:

• Chromium Installer

Chromium Autostart slår automatisk kiosk-tilstand til, men ikke inkognito.

Hvis du benytter skærmtastatur-scriptet og genkører dette script, skal skærmtastatur-scriptet køres igen herefter.

Scriptet kræver en genstart før det tager effekt.

Dette script er blevet testet og virker på Ubuntu 22.04.

Parametre

Der angives en forsinkelse før browseren startes, der kan hjælpe med at løse evt. timing issues (som regel virker det fint med 1 sekund, der angives ved tallet 1).

Skærmens højde og bredde skal sættes til skærmens korrekte opløsning.

Desuden skal der angives en orientering, som kan være “left”, “right” eller “normal”.