Flatpak is a universal application packaging standard for Linux. It allows devs to create a single application that gets bundled with all necessary dependencies including versioning.
These apps run in their own semi-isolated “container” which makes immutable distros possible. (Distros like Fedora Silverblue that are effectively impossible to break by installing or removing critical system files.)
This means that a Linux app doesn’t have to have a .deb version, an .rpm version, or be pre-compiled for any other distros. A user can simply go to Flathub, (the main repository for Flatpak apps), download the flatpak, and install it on their distro of choice.
It’s quickly becoming the most popular way for users to install apps on Linux because it’s so easy and quick. But there are a few downsides like size on disk, first party verification, per-distro optimizations, and the centralization of application sources. That’s why some users aren’t fully endorsing or embracing how popular they are becoming.
Cool, thanks for the explanation.
a single application that gets bundled with all necessary dependencies including versioning
Does that mean that if I were to install Application A and Application B that both have dependency to package C version 1.2.3 I then would have package C (and all of its possible sub dependencies) twice on my disk? I don’t know how much external dependencies applications on Linux usually have but doesn’t that have the potential to waste huge amounts of disk space?
Essentially yes, if you start using lots if older applications or mixing applications that use many different dependency versions, you will start to use lots of extra disk space because the different apps have to use their own separate dependency trees and so forth.
This doesn’t mean it will be like 2x-3x the size as traditional packages, but from what I’ve seen, it could definitely be 10-20% larger on disk. Not a huge deal for most people, but if you have limited disk space for one reason or another, it could be a problem.
It CAN get pretty wild sometimes, though. For example, Flameshot (screenshotting utility) is only ~560KB as a system package, while its flatpak version is ~1.4GB (almost 2.5k times as big)
on a desktop it might not be significant but I tried using flatpak apps on a device with very limited root emmc storage (16 GB) and ran out of space really fast. Its really common to see a couple multi-hundred-megabyte library downloads for each new app IME.
I like them for some stuff but there are glaring issues that I don’t like. I’ve posted about it before, poor integration of apps/not getting the right permissions is a big problem, the people packaging them don’t often do as good of a job as someone like a distro maintainer.
But admittedly my experience using it probably isn’t representative (pop os through their shop and arch on a mobile device). Neither were amazing, but not having to compile shit myself or install with an untrusted shell script was nice for some apps. Without some significant improvements it’s not a good replacement for a distro’s package repos but it might be a good way to broaden the available applications without having to maintain 10x more packages.
It’s not quite that simple.
Each package can choose one from a handful of runtimes to use, each of which include common dependencies (like gnome or qt libraries), and if multiple flatpaks use the same runtime, that runtime is only downloaded once.
It is less space efficient than your typical package manager, but brings other benefits like sandboxing.
Not necessarily. GNOME and KDE dependencies and “base system” for flatpaks to run in are flatpaks themselves so apps that depend on them will not use duplicated dependencies. Storage usage may not be as efficient as using a traditional package manager but you don’t install a new OS per app either.
What about those apps using out of date libraries? Wouldn’t that become a security issue - since containers usually aren’t that secure, right? And all app developers would have to update their container libraries separately, instead of just updating the system libraries?
As containers are isolated - it’s mostly a security issue for the container itself. It may become an issue, though, if the container is allowed to freely interact with filesystem, for example.
Apps like Flatseal allow you to easily control such variables using a GUI instead of tinkering in the terminal.
Interesting breakdown, thank you.
Do you happen to know if the containerization is similar to docker containers? Or more like android apps?
It’s more like android apps from early versions of Android before the permissions became user-managable.
It won’t prompt you to give the application access to certain permissions, all the permissions are predefined in the manifest by whoever published the application to flathub. When you run the application you just hope it won’t cause too much havoc (you can of course verify the permissions before running it, but I guarantee most people won’t)
Flatpak supports sandboxing but due to how most desktop applications want access to your home folder, network etc many apps simply disable it.
Regardless of the level of sandboxing applied to the app, Flatpak is a great way for a developer to package once run anywhere. Prior to Flatpak, if you wanted to support multiple distros, you had to build a package for each distro or hope somebody working on that distro would do it for you.
Inb4 AppImage was here first. And if you mention Snap then GTFO
Appimage is probably the most similar to a naked .exe in Windows. They are useful for small apps or simple indie games, but I prefer Flatpaks for my everyday big applications.
Agreed, Snaps are like Flatpaks but worse because locked down back end and Canonical’s sketchy nature. Imagine a really delicious pastry that anybody can make and sell, then imagine the same pastry but only one bakery in the world can make and sell it. Which would you prefer? Lol
I’m not an expert, but from my understanding, more like android apps.
They aren’t totally isolated like a docker or LXC container would be, but they are generally self-contained.
The Linux Experiment has a really great vid that goes into detail on all common packaging formats in Linux including Flatpaks:
