How to do kiosk mode in Ubuntu 20.04?

[orangethrift]

I'm writing a fancy touchscreen app that will run on a tablet running Ubuntu 20.04 x64. The tablet is dedicated to running the app, nothing else is of importance. I'm interested in the easiest way to get my app to run in "kiosk mode".

So things like:

1. At startup, boot straight into my app in fullscreen mode, without login
2. If possible, don't show any desktop even for a fraction of a second. There shouldn't be the concept of a desktop.
3. On app crash, auto-restart the app
4. Disable all screensavers and locks
5. When the system is powered on, I'd like to show a custom splash screen during boot with the app's logo, not the Ubuntu boot sequence.
6. Prevent user from closing the app (it's a tablet, but it has a USB port so someone could plug in a keyboard and press Alt+F4)

I can hack together solutions to all of these (systemd service/unit file, disabling USB in kernel boot flag, etc), the ones I have no clue about being #2. I'm just wondering if there's a smarter solution designed for this problem that I should be using to do what I want, instead of doing 6 different things manually.

[Holger_Gehrke]

Unless your app needs the infrastructure a full desktop distribution like Ubuntu provides, I'd take a hard look at the way specialist one-purpose distributions like OpenElec or retropie (both of these are mainly for the Raspberry Pi, but the principles are the same) do things. For 2. you probably want to run pure X without even a window manager (which should also take care of most of 6.).

Holger

[dragonfly41]

Could an Electron kiosk app meet part of your requirements?

I use Atom editor for Electron app development.

You can develop app to have frameless window.

Further customisation might come from Cubic at a guess.

[P.S.] regarding #5 custom splash screen I find that rEFInd is good for that.
Custom themes then go in /boot/efi/EFI/refind/refind.conf

[orangethrift]

Unless your app needs the infrastructure a full desktop distribution like Ubuntu provides, I'd take a hard look at the way specialist one-purpose distributions like OpenElec or retropie (both of these are mainly for the Raspberry Pi, but the principles are the same) do things. For 2. you probably want to run pure X without even a window manager (which should also take care of most of 6.).

Holger

I considered this, but:

a) I would lose the familiarity I already have with Ubuntu
b) it would be less polished/stable than Ubuntu. Ubuntu has tons of engineers working on it and is used by tens of thousands of people, resulting in a very stable, battle-tested whole. My app isn't just a basic display app, it uses a relational database, runs snmpd, might have to add web APIs one day, etc.
c) if I ever run into a big problem and need advice, Ubuntu has a huge community and even paid technical support
d) I don't like the idea of the user's OS being different from the developer's OS, it lowers productivity

[HermanAB]

The easiest way to create a kiosk, is to enable the Guest Account.

[C.S.Cameron]

GUEST ACCOUNT ON PERSISTENT INSTALL

If powering the kiosk with a persistent Live USB see:

https://askubuntu.com/questions/1223...223764#1223764

You might also want to check out Ubuntu Core: https://ubuntu.com/core

[deadflowr]

Related to Ubuntu Core see:
https://ubuntu.com/tutorials/secure-...osk#1-overview

[HermanAB]

Lahk ah sed - the Guest Account pretty much *is* a Kiosk system. Just enable it and you are done. That will take about 5 seconds tops.

[C.S.Cameron]

Herman
Is Guest Account running on off the shelf 20.04 or do we need to install lightdm first?
I understood Ubuntu switched to GDM with 16.10.

[HermanAB]

It’s been a while since I used it on Ubuntu. A few years ago, it worked fine. The same thing is also available on Mac and FreeBSD.