Revision as of 15:12, 14 January 2025

Move Fedora CoreOS updates from OSTree to OCI

This is a proposed Change for Fedora Linux.
This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee.

Summary

Change Fedora CoreOS to receive updates from quay.io/fedora/fedora-coreos instead of the Fedora OSTree repository.

Owner

Name/Email: Jean-Baptiste Trystram, jbtrystram@redhat.com
Name/Email: Timothée Ravier, siosm@fedoraproject.org
Name/Email: Jonathan Lebon, jonathan@jlebon.com
Name/Email: Dusty Mabe, dusty@dustymabe.com

Current status

Targeted release: Fedora Linux 42
Last updated: 2025-01-14
[<link to devel-announce post will be added by Wrangler> Announced]
[<will be assigned by the Wrangler> Discussion thread]
FESCo issue: <will be assigned by the Wrangler>
Tracker bug: <will be assigned by the Wrangler>
Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

Currently, Fedora CoreOS hosts pull updates from the OSTree repository. With this change, the hosts will pull updates from the Quay.io container registry instead. At first, this should be a transparent change. We will notably keep using rpm-ostree for updates (and not yet bootc).

This is preliminary work to switching to bootc to manage the system and will enable us to deliver the following changes in the future:

Moving from rpm-ostree to bootc, which only supports OCI.
Better support for mirroring updates in disconnected setups.
Moving away from maintaining a Cincinnati server towards having the graph live in an OCI registry alongside the update payload. This also allows users to maintain their own update graphs.
Users will be able to create their own customized versions of Fedora CoreOS by building a derived container image.

Feedback

None yet.

Benefit to Fedora

Alignment with the work happening in the Bootable Containers initiative.

Scope

Proposal owners:
- Publish an upgrade graph containing the digest pullspec for each FCOS release. This mirrors the current update graph containing the same information, but pointing at OSTree commit checksums.
- Change new nodes on next to use OCI from the start.
- After a number of FCOS releases, ship a migration script to switch existing next nodes to use OCI.
- Repeat the last two steps for testing, and then stable.
- Down the line, stop publishing new OSTree commits to the OSTree repo. This will not happen until at least f43.

Other developers: N/A (not needed for this Change)
Release engineering: N/A (not needed for this Change)
Policies and guidelines: N/A (not needed for this Change)
Trademark approval: N/A (not needed for this Change)
Alignment with the Fedora Strategy:
- Part of the work to align with Bootable Containers

Upgrade/compatibility impact

We will issue a barrier release to migrate users to switch to OCI images.

How To Test

Once the changes are ready, they will be enabled for the next stream.

A good "how to test" should answer these four questions:

User Experience

This change won't be visible to users running auto-updates, except cosmetic changes in rpm-ostree status output.

Contingency Plan

Revert the change to switch back to the OSTree repo. Both will be active until the Fedora 43 release.

Documentation

https://github.com/coreos/fedora-coreos-tracker/issues/1823

Release Notes

@@ Line 76: / Line 76: @@
 We will issue a barrier release to migrate users to switch to OCI images.
-== Early Testing (Optional) ==
-<!-- This is an optional step for system-wide changes to avail of. If you would like to build an initial proof of concept of your change and have a member of Fedora QA help you write and/or run some initial basic tests on your code, please email tests@fedoraproject.org and include the link to your change proposal. This step is *optional*. -->
-Do you require 'QA Blueprint' support? Y/N <!-- Optional Step for System-Wide Changes only -->
 == How To Test ==
-Once the changes are ready, they will be enabled for the *next* stream.
+Once the changes are ready, they will be enabled for the '''next''' stream.
-<!-- This does not need to be a full-fledged document. Describe the dimensions of tests that this change implementation is expected to pass when it is done.  This can be based off of the above section if early testing has been completed. If it needs to be tested with different hardware or software configurations, indicate them.  The more specific you can be, the better the community testing can be.
-Remember that you are writing this how to for interested testers to use to check out your change implementation - documenting what you do for testing is OK, but it's much better to document what *I* can do to test your change.
 A good "how to test" should answer these four questions:
-. What special hardware / data / etc. is needed (if any)?
-. How do I prepare my system to test this change? What packages
-need to be installed, config files edited, etc.?
-. What specific actions do I perform to check that the change is
-working like it's supposed to?
-. What are the expected results of those actions?
--->
-<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
 == User Experience ==
@@ Line 116: / Line 97: @@
 This change won't be visible to users running auto-updates, except cosmetic changes in `rpm-ostree status` output.
-== Dependencies ==
-<!-- What other packages (RPMs) depend on this package?  Are there changes outside the developers' control on which completion of this change depends?  In other words, completion of another change owned by someone else and might cause you to not be able to finish on time or that you would need to coordinate?  Other upstream projects like the kernel (if this is not a kernel change)? -->
-<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
-N/A. We (the coreOS Team) own the zincati package that needs to be updated.
 == Contingency Plan ==

Search

Changes/CoreOSOstree2OCIUpdates: Difference between revisions