Introducing: the dnf module

When BlueBuild was created, Fedora Atomic only used rpm-ostree to build images, install packages, and manage installed systems. rpm-ostree is basically a mash-up of libostree and libdnf, which was made to handle composing OSTree images and managing OSTree-based systems, while existing in the RPM ecosystem.

However, focus slowly shifted to enabling bootable native container images based on the OCI standard, allowing the usage of standard tools such as docker or buildah to build images. This lessened the need for rpm-ostree as a separate build tool for the images, since it was now just called from the OCI container build process, just like any other package manager. Additionally, the lackluster UX and potentially confusing architecture were starting to show, and for example, dependency resolution had issues not present in dnf.

This made the Fedora project shift towards replacing rpm-ostree with dnf5, which would be updated to handle package management on OSTree-based systems, and bootc, which would handle deploying the bootable container images alongside system administration tasks such as updating and switching base images. Since F41, bootc and dnf5 have been included in all official images and are now the main way to build and manage Atomic systems, replacing rpm-ostree.

The dnf module

For the past few months, the BlueBuild team has been working on a new module called dnf that works as a repository and package management wrapper for dnf5 (and dnf4 if dnf5 isn’t available). The configuration structure for the module has been designed from the ground up to be intuitive and featureful. New features compared to the rpm-ostree module are, for example, package group installation, installing packages from specific repositories, and managing COPR repositories.

The module is a part of our new batch of modules that are written in Nushell, a modern shell that is built on top of the Rust programming language. This approach makes the modules more maintainable and the source code more readable. You can read more about this change and decision process in the GitHub Issue and possibly a future blog post.

And yes, it can install Steam (this was a headache with rpm-ostree because of dependency resolution issues).

type: dnf
repos:
  files:
    - https://negativo17.org/repos/fedora-steam.repo
install:
  packages:
    - install-weak-deps: false
      packages:
        - steam
        - kernel-modules-extra

Switching from rpm-ostree to dnf

To switch to the dnf module, switch the module type from rpm-ostree to dnf. Make sure to check out the module reference page to see how to use the new module. Below is a short list of the main differences between the two modules.

• Changes to the repos: section
  • The rpm-ostree module used to have a repos: section that was a list of repo files.
  • The dnf module’s repos: section supports adding repositories from files and COPR directly, adding repository keys, and choosing a nonfree repository (rpmfusion or negativo17).
  • The section repos: files: in the dnf module is equivalent to the repos: section in the rpm-ostree module.
  • The proper way to add COPR repositories is to use the repos: copr: section in the dnf module.
• Changes to the install: and remove: sections
  • The rpm-ostree module used to have install: and remove: sections that were lists of packages to install/remove.
  • The dnf module’s install: and remove: sections support setting flags for the package manager.
  • The section install: packages: in the dnf module is equivalent to the install: section in the rpm-ostree module.
  • The list of packages also supports including sublists of packages to install from a specific repository or with specific flags.
• Changes to the replace: section
  • While the syntax remains the same, the replace: section in the dnf module supports setting flags for the package manager.
  • The from-repo: parameter now takes the name of the repository to replace from, and the repository has to be added earlier in the repos: section.
• New sections
  • The group-install: and group-remove: sections are new to the dnf module.

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Published on 2025-04-27.
Authors:

xyny
@xynydev