Quoting DNF PO: "DNF 5 is rewrite of DNF 4 in C++, all is changing, will be included in RHEL 10"

DNF5 is planned to land in Fedora 39 (now rawhide) and it seems to be a complete rework of DNF, including it's API and Python bindings.

The change has potentially a high chance to break `dnf-json` and depsolving part in osbuild-composer. We need to test depsolving and image building with DNF5 and make necessary changes for osbuild-composer to keep working on new Fedora releases and in RHEL-10

This Epic is about investigating the actual impact and taking necessary steps for image builder to keep working with DNF5.

Goal:

• Assess and test the impact of DNF5 changes on image package set depsolving and thus image building in osbuild-composer.
• Determine necessary changes in osbuild-composer, so that it works with DNF5, but also keeps working with DNF4 (el8 and el9).
• Implement the changes in osbuild-composer in time for Fedora 39 

Acceptance Criteria:

• osbuild-composer can successfully depsolve image package sets and build images with DNF5 installed on Fedora 39 as well as on older Fedora releases and RHEL-8 and RHEL-9.

Open questions:

• What's the impact of DNF5 Python bindings changes on depsolving in osbuild-composer (dnf-json)?

Additional infromation:

• DNF 5 repo - https://github.com/rpm-software-management/dnf5

• Fedora changes
  • https://fedoraproject.org/wiki/Changes/ReplaceDnfWithDnf5
  • https://fedoraproject.org/wiki/Changes/MajorUpgradeOfMicrodnf
• Fedora 39 schedule - https://fedorapeople.org/groups/schedule/f-39/f-39-key-tasks.html

Contacts:

• mcurlej (DNF PO)