Shipping configuation as a snap

[Saviq]

Hi all,

With snaps we have a great solution for delivering software to devices, has anyone considered using snaps as a way to deliver configuration as well? When dealing with a significant number of devices, you probably want to avoid having to configure them directly, and that’s where a gadget snap comes in handy.

I don’t think you can update a device by means of updating a gadget snap, can you?

This could be as simple as introducing a config interface and allowing that snap run snap config (as opposed to snapctl config), or as complex as supporting upgrades of the gadget snap, including snap removal and installation.

Thoughts? Am I completely off the rails here?

[ogra]

if it is only configuration via snap config you can indeed already use a gadget snap today … note though that gardget snaps currently only update these metadata files (the configure and prepare-device hooks too i think) and no payload content …

neither of the below has being worked on yet i think…

Automatic gadget asset updates

One of the requests we get from integrators is to allow to update assets in the gadget snap. The gadget snap is currently updated (like any other snap). However the parts described in meta/gadget.yaml is only read on image provisioning (example: https://github.com/snapcore/pc-amd64-gadget/blob/master/gadget.yaml). I propose we add a new yaml key under “content” that allows to specify “auto-refresh: true” as an opt-in. If snapd finds content with this option it will copy those files from the ga…

Updating bootloader assets in the gadget snap

Background The gadget snaps typically contain bootloader files like e.g. bcm2709-rpi-2-b.dtb that is critical for the system to boot. Those files are put in place by ubuntu-image on image creation time, e.g. to /boot/uboot/bcm2709-rpi-2-b.dtb. Subsequent updates of the gadget snap via snapd will not modify these files currently. Sometimes it is important to provide updates to those files and snapd should support this. Possible options Updating the bootloader files is very dangerous, if the pow…

for an example regarding device configuration see the “defaults” section in:

ogra1/beaglebone-gadget/blob/master/gadget.yaml