How to make audio devices available with guix shell --container

[Elias Kueny <elias.kueny@posteo.net>]

Hello,

I'm trying to run an online videoconferencing tool in chromium in a guix shell with a container, so I expose my system as little as possible. All is well without the --container option, but I'm not sure what to expose to make it work in the container too.

I'm on guix system. I'm starting the software with: `guix shell --container -N -P --no-cwd --preserve='^DISPLAY$' --preserve='^XAUTHORITY$' --share=$XAUTHORITY --share=/dev/video0 ungoogled-chromium -- chromium --app="https://meet.jit.si"`.

`--preserve='^DISPLAY$' --preserve='^XAUTHORITY$' --share=$XAUTHORITY` lets chromium open an X window and share the scren.
`--share=/dev/video0` gives access to the webcam.
What is the step to allow the microphone and speakers?

I'm not particularly familiar with how audio devices are working. I read they are in /dev/snd, but sharing this or even the whole of /dev/ doesn't make the microphone and speakers available (although the browser is now asking me for the permission to access them, so it seems aware I have them). I also tried adding tinyalsa and pulseaudio to the container in case that's what's missing, but to no avail. I didn't explicitely install anything related to audio (but I have %desktop-services in my operating-system definition), so if it's a software that is missing, I don't know which one.

Thank you in advance!