At the Linux Application Summit (LAS) in April, Sebastian Wick said that, by many metrics, Flatpak is doing great. The Flatpak application-packaging format is popular with upstream developers, and with many users. More and more applications are being published in the Flathub application store, and the format is even being adopted by Linux distributions like Fedora. However, he worried that work on the Flatpak project itself had stagnated, and that there were too few developers able to review and merge code beyond basic maintenance.
I was not able to attend LAS in person or watch it live-streamed, so I watched the YouTube video of the talk. The slides are available from the talk page. Wick is a member of the GNOME Project and a Red Hat employee who works on “all kinds of desktop plumbing
“, including Flatpak and desktop portals.
Flatpak basics
Flatpak was originally developed by Alexander Larsson, who had been working on similar projects stretching back to 2007. The first release was as XDG-App in 2015. It was renamed to Flatpak in 2016, a nod to IKEA’s “flatpacks” for delivering furniture.
The Flatpak project provides command-line tools for managing and running Flatpak applications, tools for building Flatpak bundles, and runtimes that provide components for Flatpak applications. The project uses control groups, namespaces, bind mounts, seccomp, and Bubblewrap to provide application isolation (“sandboxing”). Flatpak content is primarily delivered using OSTree, though support for using Open Container Initiative (OCI) images has been available since 2018 and is used by Fedora for its Flatpak applications. The “Under the Hood” page from Flatpak’s documentation provides a good overview of how the pieces fit together.
Slowing development
Wick started his talk by saying that it looks like everything is great with the Flatpak project, but if one looks deeper, “you will notice that it’s not being actively developed anymore
“. There are people who maintain the code base and fix security issues, for example, but “bigger changes are not really happening anymore
“. He said that there are a bunch of merge requests for new features, but no one feels responsible for reviewing them, and that is kind of problematic.
The reason for the lack of reviewers is that key people, such as Larsson, have left the project. Every now and then, Wick said, Larsson may get involved if it’s necessary, but he is basically not part of the day-to-day development of the project. Wick said that it is hard to get new Flatpak contributors involved because it can take months to get feedback on major changes, and then more months to get another review. “This is really not a great way to get someone up to speed, and it’s not a great situation to be in
.”
“Maybe I’m complaining about something that is actually not that much of an issue
“, he said. Flatpak works; it does its job, and “we just use it and don’t think about it much
“. In that sense, the project is in a good spot. But he has still been thinking about how the project is “living with constraints
” because contributors do not have the opportunity to go in and make bigger changes.
As an example, Wick said that Red Hat has been doing work that would allow Flatpaks to be installed as part of a base installation. The vendor or administrator could specify the applications to be installed, and a program called flatpak-preinstall would take care of the rest. The feature has been implemented and is planned for inclusion in Red Hat Enterprise Linux (RHEL) 10. The work was started by Kalev Lember and Owen Taylor last June, but the original pull request was closed by Lember in February as he was leaving Red Hat and would not be working on it anymore. It was picked up by Wick in February as a new request but wasn’t reviewed until early May.
