Support for qtype_stack in Moodlebox

Chris Sangwin

First, thank you very much for supporting Moodlebox. It's a really exciting development.

I'm the instigator of qtype_stack. This is a highly sophisticated mathematical question type for moodle, and is very widely used. We have a community site here: https://stack-assessment.org/

STACK is very widely used in low-resource environments, and we have a highly active user group in Africa (e.g. the most recent conference is here, https://stack-assessment.org/CaseStudies/2024/African_STACK_Conference_2024/ and our advisory group is https://stack-assessment.org/Communities/African_leadership/)

Would it be possible to ship moodlebox with qtype_stack?

I will support this, and help installation (which is non-standard). Happy to chat in person if this helps.

Thanks again!

Chris Sangwin
C.J.Sangwin@ed.ac.uk

Nicolas

What an honour to have you in person on this forum 😊 (Don't know if you remember: I'd the pleasure to meet you in person at MoodleDACH 2023 in Zurich, and to attend your STACK workshop).

I think it's a good idea to have qtype_stack pre-installed in MoodleBox, and I'm thinking of it for a few months. With the help of instructions given by @marcus, I've a stable manual procedure to install it, and STACK works pretty well at least on a RPi 5 (I've had no time to test this on other RPi models).

After having thought a few days about it, my main concerns are below. I'd be happy to have feedback and thoughts about it from you (and others).

Image build

The build process uses Ansible, and I want to keep it this way, since it makes the build quick and reproducible. (As you surely know, this project is done on my spare time.)

Installing the qtype_stack plugin and its dependencies from Github sources, as well as setting the options needed is not a problem.
Building automatically a goemaxima docker image is more challenging. Optimally, I'd like to be able to download an up-to-date docker image and install it directly, without the hassle to build it. <-- Help needed here
Setting a systemd service to run the docker image at startup is ok. I'm favoring Podman for this, since it's easier to install than Docker.
Bigger size of the image (not a big problem).

Image update for users in the field

This is IMHO more challenging, and I do not know the answers to this (I'm quite new to Docker). But this is less important and could be achieved later.

How to be sure, when a user updates Moodle and/or qtype_stack, that the goemaxima image is still compatible?
How to enable a user to update the goemaxima docker image?

Chris Sangwin

Thanks for such a quick reply. I don't think goemaxima is needed for this application, since everything is self-contained. We can just use the "optimised" direct connection. That's what I did on my moodlebox (which worked great, right out of the box!) If you'd like a demo/detailed explanation then we can set up a zoom call. Perhaps we could arrange that by email?

ralfkrause

Hi, if I understand the using of STACK correctly then the plugin qtype_stack is a connection to an external STACK server. Is this correct? In a lot of use cases the MoodleBox works without an internet connection and the MoodleBox can't use an external internet server.

Ralf

Chris Sangwin

Ralf, qtype_stack has a number of options. The issue is using Maxima (https://maxima.sourceforge.io/) as a stateless function for mathematics.

The default is to be entirely self-contained, with Maxima installed on the same server. I set up my moodlebox this way, and it installed perfectly first time. This worked for moodlebox, e.g. with "apt-get install maxima" I think from memory. (The real challenge was figuring out how to SSH into the moodlebox initially!).

We have an option to connect to an external server, currently goemaxima is recommended and supported. This is really for scalability, and to separate out executing the Maxima process on the same machine as the PHP scripts. This is really similar to having an external DB.

I recommend the first option for moodlebox - it's simpler, self contained, and adequate security in this application. Happy to demonstrate on a zoom call.

Chris