Saturday, May 20, 2023

Porteus Kiosk

Porteus Kiosk is a software product that can be used to turn computers into “dumb” terminals that serve a single purpose. For example, showing a slide show on a large monitor in a hotel lobby or allowing customers to make appointments at a hair salon. It uses a very light-weight Linux operating system and utilizes either the Firefox or Chrome web browser. It only requires only 1 GB of hard disk space and 1 GB of RAM.

At the public library where I work, this product is perfect for the computers that patrons use to look up items in the library’s online catalog (referred to as "OPACs"--online public access catalogs). Gone are the days of jumping through a thousand hoops trying to properly lock down and administer an expensive and resource-heavy Windows computer. Porteus Kiosk is better in every way.

The way it works is you burn a 170 MB ISO to a flash drive (or an optical disk if you’re feeling nostalgic) and boot the flash drive on the kiosk computer. The kiosk image is configured using a special configuration file, which is just a plain text file with one setting per line. All of the settings are documented on their website.

Example configuration file:


The setup wizard allows you to provide this configuration file, but it also provides a user-friendly GUI that allows you to browse the various configuration settings that are available and set them as you wish. When you are done, it shows you the configuration file that it generates based on the settings you selected. You can then save it for later use.

Once the configuration settings have been provided, it prompts you to choose a partition on the hard drive on which to burn the kiosk image. You might think it would take a while to write an entire operating system to the hard drive, but it is very fast. On the 10+ year old machines I’ve put Porteus on, it takes less than a minute.

In order to reconfigure the kiosk (for example, changing the home page), you have to go through the entire process again—there’s no “administration settings” screen you can open while the kiosk is running. However, it is possible to host the configuration file on a web server and point the kiosk to this URL. When this is done, every time the kiosk boots, it checks to see if the configuration file has changed. If it has, it automatically re-images the machine with the new configuration. If it is unable to download the configuration file (due to the web server being down, for instance), it continues to use the last configuration file it downloaded and displays a warning message at the top of the screen for a few seconds after it boots.

Despite all the great things about Porteus, I did encounter one annoying issue related to the system clock. I have configured our computers to turn on automatically in the morning using the Auto-On settings in the BIOS. Every time the computer boots, Porteus syncs the system clock with internet time servers. This is good because most websites use HTTPS, and if the system clock is not set correctly, these sites will not load. However, it sets the system clock to UTC time, which means that the Auto-On time, which is defined in local time, no longer matches the system clock time. A workaround is to set the Auto-On time to be 4 hours ahead of local time (for example, setting it to 12 PM when I want the computers to turn on at 8 AM). However, this means that the computer will turn on an hour early during the other half of the year when our UTC offset is -5 instead of -4.