Gadget snap default config values don't work reliably

[Tony Espy]

Default settings of snap inside gadget can't work

Currently, gadget includes the following default settings:
1. wifi-ap - automatic-setup.disable: true
2. udisks2 - automount.enable: true

When we tested the latest image to verify the default settings from gadget, the result was that values weren't set correctly, even also base image. So it suspects there's a race condition to happen this case.

This is being reported as of snapd version 2.23.1.

[Tony Espy (awe)]

Changing this to Confirmed, as we actually had to implement a workaround via the first boot hook due to this bug.

[Simon Fels (morphis)]

I've already spoken with Samuele about this. This is not in general broken. If default configuration is present in the gadget snap is used and correctly applied. However this isn't true when a device is booted the first time and the seed is exercise. There is no ordering for seeded snaps yet so the gadget snap is not taken first and default configuration extracted and applied for all subsequently installed snaps. See https://github.com/snapcore/snapd/blob/master/overlord/snapstate/snapstate.go#L223 for more details on this.

[Renat (renat2017)]

Hi!

I confirm that it doesn't work for us too.

For our rabpberrypis we use:

defaults:
  core:
    pi-config.gpu-mem: 512
    pi-config.gpu-mem-256: 128
    pi-config.gpu-mem-512: 256
    pi-config.hdmi-drive: 0
    pi-config.hdmi-force-hotplug: 1
    pi-config.hdmi-group: 0
    pi-config.hdmi-mode: 0
    pi-config.framebuffer-depth: 32
    pi-config.framebuffer-height: 0
    pi-config.framebuffer-ignore-alpha: 1
    pi-config.framebuffer-width: 0

settings to setup our node on the first boot. That's important because if we don't set gpu_mem correctly on the first boot - on the second boot our soft won't work.

We supply a default config for pi in our gadget snap, but it's overridden during the first boot.

[Samuele Pedroni (pedronis)]

renat: notice that even once fixed you need to use the snap-id of core, not "core" in the defaults key

[Samuele Pedroni (pedronis)]

working on fixing this

[Samuele Pedroni (pedronis)]

a fix has landed and should be in 2.27