Changes/DNFAndBootcInImageModeFedora

DNF and bootc in Image Mode Fedora variants

Summary

Enhance the image-mode Fedora user experience by providing familiar DNF commands on client side and inside a container image build. Provide DNF5 alongside rpm-ostree while we slowly port functionality from rpm-ostree to DNF5.

DNF5 can be used in most cases during container builds (Containerfile/Dockerfiles) for a familiar UX. Initially DNF will point users to use rpm-ostree on a booted image-based/ostree system.

For Fedora 41, we will provide DNF5 on image-based Fedora variants (Atomic desktops, Fedora IoT, etc). We will update all layering examples to use dnf during build time when possible. Additionally to DNF we will still provide rpm-ostree as the main tool for package layering on the client side and bootc to manage transactional, in-place operating system updates using OCI/Docker container images.

DNF5 will provide a helpful error when running on an ostree/image-based booted system pointing to use rpm-ostree or to unlock the system.

This work is part of the Fedora Bootable Containers Initiative.

Owner

• Joseph Marrero, jmarrero@fedoraproject.org
• Colin Walters
• David Cantrell
• Timothée Ravier, siosm@fedoraproject.org
• Jonathan Lebon
• Renata Ravanelli

Current status

DNF5 when installed on a image-based/ostree system can be used to install RPMs if the system is unlocked, it also works on most container builds, one major exception at the moment are kernel installations and kernel updates. DNF is not part of image variants at the moment, however CoreOS is exploring adding it via: https://github.com/coreos/fedora-coreos-tracker/issues/1687

Bootc allows system admins to deploy bootable containers and it's available on the Fedora repositories.

• Targeted release: Fedora Linux 41
• Last updated: 2024-06-21
• Announced
• Discussion thread
• FESCo issue: #3216
• Tracker bug: #2293627
• Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

Having the Fedora ecosystem (from users to release engineering) move away from DNF on image-based systems has had mixed results as it has forced sysadmins and users to not use DNF as they are accustomed to and learn a new tool to do RPM package management in their systems. This change proposal starts the process of making DNF the client side tool to manage RPMs on image-based systems in the future. To start we will provide the DNF5 package alongside rpm-ostree, giving sysadmins and users the ability to use DNF on their container builds and unlocked systems running image-based Fedora variants. We will also provide bootc to manage the image-based deployments and updates.

This proposes that:

• DNF5 is included on image-based/ostree Fedora variants.
• DNF5 is updated to point users to rpm-ostree on booted client systems when invoked.
• rpm-ostree features will start being ported to DNF5.
• We support deriving new user custom images from image-based Fedora images and installing software using DNF during builds.
• We ship bootc on all Fedora image-based variants.

Feedback

None so far.

Benefit to Fedora

• A familiar UX for rpms during container builds of image-based Fedora.
• A new dedicated tool for image-based system updates management that follows the *nix ethos of using one thing and doing it well.
• An initial use of DNF on booted image-based systems when the system is unlocked.

Scope

• Proposal owners:
  • Add DNF5 and bootc on all image-based/ostree variants.
  • Update DNF5 error message when called on a booted image-based/ostree system
• Other developers:
  • The "other" here is vague, but certainly developing this so far has needed cooperation with e.g. the containers, coreos and dnf organizations etc.
• Release engineering: Probably nothing needed so N/A #Releng issue number
• Policies and guidelines: N/A (not needed for this Change)
• Trademark approval: N/A (not needed for this Change)
• Alignment with the Fedora Strategy: Aligns with the work to improve Image Mode variants of Fedora

Upgrade/compatibility impact

Each edition/spin will include bootc and dnf(DNF5). However rpm-ostree will still be present, which means there is no upgrade/compatibility impact, we are adding additional tools not removing tools or functionality.

Early Testing (Optional)

Do you require 'QA Blueprint' support? No

How To Test

On a booted image-based host, run: dnf install <package> and bootc status

Inside a Dockerfile/Containerfile with a image-based Fedora variant as a base image, add a package using dnf: RUN dnf install <package>

User Experience

Users of image-based Fedora variants will be able to use the dnf command on Container builds and unlocked systems.

Dependencies

N/A

Contingency Plan

• Contingency mechanism: Continue to ship without DNF in some or all image-based/ostree variants.
• Contingency deadline: Beta freeze.
• Blocks release? No

Documentation

• https://dnf5.readthedocs.io/en/latest/
• https://containers.github.io/bootc/

Release Notes

Starting Fedora 41, the Fedora Atomic Desktops, Fedora CoreOS and Fedora IOT will ship bootc and DNF5 as part of the image. Now you can use dnf commands as part of container builds that use these Fedora variants as the base image. While rpm-ostree is still available you can now use bootc to manage your image mode deployments and updates.

When running dnf on a booted image mode system dnf will give a better error message pointing to the available tools on your booted system to accomplish your task.This is the start of a process to enable dnf with rpm-ostree features and the re-focus on bootc to manage image mode deployments.