Running Chromium as a Dashboard

2015-01-28 08:26:00 +0000

On my desk I have a dashboard (an “information radiator”) that displays various useful things, such as the build status of various Jenkins jobs, clocks showing important timezones (Electric Imp is a distributed company), and so on.

It’s built from an Acer nettop, and it runs Chromium in kiosk mode. Here’s how I got it to start everything automatically.

Dashboard Web Server

The dashboard is implemented using dashing, and I use an upstart script (in /etc/init/dashing.conf) to ensure that it’s running at bootup:

#!upstart
description "Dashing dashboards"
author "Roger Lipscombe"

respawn
start on runlevel [23]

setuid dashboard
setgid dashboard

script
  cd /home/dashboard/dashboard/
  dashing start
end script

Note that the script assumes that you have a dashboard user, and that dashing is installed in /home/dashboard/dashboard.

Starting X

Great! I’ve got a web server running the dashboard software; now I need to display it somewhere. To do this I run an X session on the box.

This is done with two files: /etc/init/startx.conf starts X:

#!upstart
description "Start X without a display manager or a window manager"
author "Roger Lipscombe"

# start/stop lifted from Mint's mdm.conf:
start on ((filesystem
           and runlevel [!06]
           and started dbus
           and (drm-device-added card0 PRIMARY_DEVICE_FOR_DISPLAY=1
                or stopped udev-fallback-graphics))
          or runlevel PREVLEVEL=S)

stop on runlevel [016]

script
    USER="dashboard"
    exec /bin/su -s /bin/sh -l -c "/usr/bin/startx" $USER
end script

Running Chromium

Chromium is then run from /home/dashboard/.xinitrc:

#!/bin/sh

# Turn off screen blanking and power saving
xset s off
xset -dpms

# Rotate the screen (optional)
xrandr --output HDMI-1 --rotate left

# Hide the mouse cursor.
unclutter -grab &

# Start the web browser, with an address...
while true; do
    # Sleep for a bit; this gives the network a chance to recover, and
    # also allows us to do stuff remotely (like clear the cache) before
    # Chrome restarts.
    sleep 5

    # See http://stackoverflow.com/q/9792667/8446
    sed -i 's/"exited_cleanly": false/"exited_cleanly": true/' \
        ~/.config/chromium/Default/Preferences

    # This doesn't go into the background, which is good.
    chromium-browser --kiosk http://localhost:3030/
done