Creating the Ubuntu Core 18 Model Assertion and Image files

I have started the transition of creating ubuntu-images using Ubuntu Core 18. So far, I have seen this “The road to core18” post with respect to updates.

I want to get an example model assertion file however I am experiencing some issues running ;

$ snap known --remote model series=16 brand-id=canonical model=core-amd64-18

I get the following error;

error: model (core-amd64-18; series:16 brand-id:canonical) not found

This page hasn’t been updated since August. I am trying to find the proper model assertion example for a simple pc-amd64 based architecture.

There is an additional post with an example model assertion: “Model assertions for core18”. When running the ubuntu-image command, I receive the following error:

error: cannot find snap "pc=18": snap not found

This is the same case for pc-kernel=18.

Thanks for the help in advance.

the actual final naming for these is ubuntu-core-18-amd64, ubuntu-core-18-pi3 etc

This looks like a too old ubuntu-image or snap command problem. Are you using the snap for ubuntu-image? it seems to contain a too old snap command.

@sil2100 what’s the best way to get an ubuntu-image that works for core18?

I updated to the latest version of ubuntu-image. It appears that this error is still an issue

@sil2100 or @pedronis, With the recent official release of core18, has anyone had any luck compiling an amd64 ubuntu core18 image via ubuntu-image?

I’m building core18 images successfully since quite a long time, both using the official and custom models. For instance I just ran this:

snap known --remote model series=16 brand-id=canonical model=ubuntu-core-18-amd64 >test.model
ubuntu-image snap -O out -d test.model

Which ended up creating an amd64 image. Tried it both with the latest deb and the current (slightly outdated) ubuntu-image snap from stable. The error message you’re getting feels to me as if our snapd is not up-to-date. Did you upgrade to the latest before running the builds?

Hi @sil2100, I have updated to the latest ubuntu-snap image. Are you compiling using Ubuntu 16.04? I’m wondering if this is will work on Ubuntu 18.04