use official upstream Atomic Desktop images (once they support bootc) insted of current unofficial

[bsherman]

We want to migrate to official upstream Fedora bootc images as the foundation for Universal Blue images.

Upstream builds:

• fedora-bootc
• fedora-kinoite
• fedora-sericea
• fedora-silverblue

These all map well to the following existing images:

• base
• kinoite
• sericea
• silverblue

So the transition would be change the "FROM" on these images from quay.io/fedora-ostree-desktops/silverblue to quay.io/fedora/fedora-silverblue etc. base would be FROM bootc.

This change is blocked until Fedora F41 enables bootupd for BIOS systems:

• https://tim.siosm.fr/blog/2024/10/30/fedora-atomic-desktops-41/#bootupd-enabled-by-default-for-uefi-systems-bios-coming-soon
• https://gitlab.com/fedora/ostree/sig/-/issues/1

The primary change to the project, other than being built from official upstream images, is we will not have official upstreams for lazurite (LXQT), onyx (Budgie), and vauxite (XFCE). So those desktops will be removed.

We should probably mark them as "deprecated" ASAP.

Notes from team discussion: Also these changes may be related:
https://pagure.io/fedora-infra/ansible/pull-request/2337
https://pagure.io/releng/issue/12142

[castrojo]

The latest lazurite-main has 21 pulls: https://github.com/ublue-os/main/pkgs/container/lazurite-main/versions

The latest vauxite-main has 92 pulls: https://github.com/ublue-os/main/pkgs/container/vauxite-main

lazurite is probably scanner noise, let's nuke it, but there's probably a handful of xfce folks on those images. Timothee says this on an official xfce image, so we can probably point to people there if they want to continue getting support.

[alexsch01]

Curious, I thought the bootc images don't allow layering, is that still true?

[bsherman]

bootc is the future of Fedora Atomic Desktops and CoreOS, so it's our future.

Local layering has never been a goal of Universal Blue as I've understood it. The vision has always been a future where that's not required. Local layering has been a painful occasional workaround.

All said, I should answer your question 😃

No bootc does not support local layering, but we will still have a container native rpm-ostree backend, so users wanting to local layer can still use rpm-ostree for that purpose.

Switching our source images is an important step but will not automatically change everything to upgrade via bootc, which is where local layers would be dropped.

[castrojo]

bootc tells the user what to do:

# bootc update
ERROR Upgrading: Deployment contains local rpm-ostree modifications; cannot upgrade via bootc. You can run `rpm-ostree reset` to undo the modifications.

[gerblesh]

As per issue: https://gitlab.com/fedora/ostree/sig/-/issues/48 and https://pagure.io/releng/issue/12142
bootc, bootupd, and dnf5 should now all be working on the official images. I'm not sure if we want to move right away, if we were to switch, we would likely have to only move images that are F41+