kiosk-browser

Ubuntu/Debian/Raspbian package to set up a system as a kiosk browser. Release announcement and example photo can be found on my blog at http://blog.schlomo.schapiro.org/2012/09/dashboards-made-easy.html.

This package disables the regular GUI and installs a browser-only GUI. Keyboards and mice are disabled to prevent tampering.

The behavior can be customized in /etc/default/kiosk-browser:

• Set KIOSK_BROWSER_START_PAGE to set the start page(s).
• Set KIOSK_BROWSER_PORTS to autoconfigure these|this display ports (Use xrandr port names)
• Set KIOSK_BROWSER_XRANDR_EXTRA_OPTS to rotate some displays or set other custom xrandr settings.
• Set KIOSK_BROWSER_WATCHDOG_TIMEOUT to the amount of seconds after which the systems reboots if the screen did not change. Default is 3600.
• Set KIOSK_BROWSER_WATCHDOG_CHECK_INTERVAL to the check interval in seconds, default is 313.
• Set KIOSK_BROWSER_SHOW_SYSTEM_MONITOR=yes to show xosview.
• Set KIOSK_BROWSER_VNC_VIEWER_DISPLAY=0 to enable a vncviewer in listening mode on port 5500.
• Add custom initialization commands or pull the above configuration from somewhere else.

The package is licensed under the GNU Public License, see included LICENSE.txt for full license text.

Building

1. Install fakeroot, lintian and dpkg.
2. Checkout this github repo and type make.
3. In out you should find the resulting .deb package file.

Installation

1. Install the .deb package you build just now from the out directory. Alternatively you can download it from the Releases of this GitHub repo or add my PPA to your system and install it from there.
2. Configure SSH access so that you don't lock yourself out of your computer
3. Create /etc/default/kiosk-browser and set KIOSK_BROWSER_START_PAGE
4. Reboot the system

If you want to play with the settings without rebooting the system you can use this command to restart the kiosk browser:

sudo kiosk-browser-control restart

Notes

• This package disables all inputs in the X server so that nobody can mess with your system or use it as an entry point into your network.

Customisation & Special Features

Multi-Monitor Support

kiosk-browser supports setting up multiple monitors with different browser windows. The implementation is somewhat tricky so that I would be happy to get some feedback on it.

Some of the above mentioned KIOSK_BROWSER_* variables can be Bash Arrays and multi-monitor support is enabled by setting these variables to arrays. In each array the same position refers to the same display, for example:

KIOSK_BROWSER_PORTS=(HDMI1 HDMI2)
KIOSK_BROWSER_XRANDR_EXTRA_OPTS=("" "--rotate left")
KIOSK_BROWSER_START_PAGE=( 
    http://blog.schlomo.schapiro.org
    http://go.schapiro.org/schlomo
)

Note the empty ("") array value which means no extra xrandr options for HDMI1. For single monitor operations you can still use these variables to configure the display, e.g.:

KIOSK_BROWSER_PORTS=VGA
KIOSK_BROWSER_XRANDR_EXTRA_OPTS="--rotate left"
KIOSK_BROWSER_START_PAGE=http://blog.schlomo.schapiro.org

If you don't know if the VGA port is called VGA or VGA1 you can specify a substring and the scripts will use the first connected port that matches. Here we basically use the fact that a Bash String is exactly the same as a Bash Array with a single value in it.

Different Browsers

The default browser is Chromium. kiosk-browser also supports Epiphany as browsers. To use a different browser set the KIOSK_BROWSER_PROGRAM variable to either epiphany. Since September 2014 epiphany has been greatly improved on Raspberry Pi so that it is worth to try it out.

Virtual Projector

If you use the kiosk-browser package to drive a large-screen team dashboard then you can also use it as a projector. Enable VNC support with the KIOSK_BROWSER_VNC_VIEWER_DISPLAY and "beam" your desktop to the screen with a VNC reverse connection (VNC server connects to the VNC client).

Linux Clients

Install x11vnc and use x11vnc -connect <HOSTNAME> to send your desktop. x11vnc has many options to fine-tune the VNC session, including scaling your desktop to fit the native resolution of the kiosk-browser screen.

Windows Clients

Install TightVNC Server and use the "Attach Listening Viewer" menu to connect.

Mac Clients

Install Vine Server (osxvnc) and add a "Reverse Connection"

Chromium Preferences

The chromium profile is wiped on each start. To set chromium preferences you can use the master_preferences mechanism and create a /usr/lib/chromium-browser/master_preferences file with preferences. For example I use

{
    "profile" : {
        "default_zoom_level" : 2.22390108574155
    }
}

to set the zoom level to 150%. This allows us to have dashboards that look fine both on my desktop and on the kiosk browser.

Show more than one page

Sometimes a dashboard should cycle between several views. I think that this should be done on the server side, not the client side. For example, create on your web server a file named urls.js like this with the URLs in it:

    var urls = [ 
            "http://www.schapiro.org/schlomo/publications",
            "http://www.schapiro.org/schlomo/videos"
            ];

And next to it another file with the HTML code, named dashboard.html:

    <!DOCTYPE html>
    <html>
    <head>
    <script type="text/javascript" src="urls.js"></script>
    <script type="text/javascript">
    
    function start() {
            setInterval(function(){cycle()},60000);
            cycle();
    }
    
    var counter = 0;
    function cycle() {
            var iframe = document.getElementById("iframe");
            iframe.src=urls[counter++];
            if (counter >= urls.length) {
                    counter = 0;
            }
    }
    
    </script>
    <style type="text/css">
    body,iframe {
            padding: 0px;
            margin: 0px;
    }
    #wrap { position:fixed; left:0; width:100%; top:0; height:100%; }
    #iframe { display: block; width:100%; height:100%; }
    </style>
    <title>Dashboard switcher by Schlomo Schapiro</title>
    </head>
    <body onload="start()">
    <div id="wrap"><iframe id="iframe" src=""/></div>
    </body>
    </html>

Finally, adjust KIOSK_BROWSER_START_PAGE in /etc/default/kiosk-browser to point to this dashboard.html and you are done.

Prevent loading

As kiosk-browser disables mouse and keyboard it can be nearly impossible to fix network connectivity problems. If you want to be able to prevent the loading of the graphical environment create /etc/systemd/system/nodm.service.d/keycheck.conf with the this content:

[Service]
ExecStartPre=/bin/sh -c "timeout 1 thd --dump /dev/input/event* | grep -q _ && exit 1 || exit 0"

As a result pressing any key or mouse button during system startup will prevent the start of nodm and the graphical environment. This trick requires the triggerhappy package which is installed by default on Raspbian.

Hacking

The kiosk-browser user session creates a temporary Home Directory under /tmp. To access the running kiosk-browser session use kiosk-browser-control interactive. In the shell you can use cd to go to the session Home Directory.