Supplemental Linux® From Scratch - Version #10af7

Chapter 3. General Utilities

Flatpak-1.16.5

Introduction to Flatpak

Flatpak allows you to download apps and run them in a sandbox. It downloads all of the dependencies of a given package in a sandbox and allows you to run the package as if it was not in a sandbox. Some packages only exist as a Flatpak, and some packages have so many dependencies that it might be better to install the Flatpak version instead.

Flatpak Dependencies

Required

AppStream, D-Bus, Fuse3, GLib, gpgme, JSON-GLib, Systemd, OSTree-2025.7 (with cURL and gpgme), p11-kit, and pyparsing

Recommended

appstream-glib, Avahi, Bubblewrap, cURL, libarchive, libseccomp, libsoup3, libXau, xdg-dbus-proxy, and xdg-desktop-portal (with libportal)

Recommended Runtime

OpenGL (libglvnd or Mesa; Mesa's GL is not supported) [3] and drivers for your GPU(s) for graphics APIs like OpenGL and Vulkan

Optional

DConf (wanted if using a GNOME app via Flatpak), Git, GTK-Doc, libxslt, malcontent (for parental features), socat-1.8.1.1 (for tests), Valgrind, and xmlto

Installation of Flatpak

If you will be running the tests, prevent the test generation from copying locale files that LFS doesn't install. On LFS systems, all of the locales are put in one archive file. 

sed -i '92,97d' tests/make-test-runtime.sh

Install Flatpak by running the following commands: 

mkdir build &&
cd    build &&

meson setup --prefix=/usr                       \
            --buildtype=release                 \
            -D system_bubblewrap=bwrap          \
            -D system_dbus_proxy=xdg-dbus-proxy \
            -D gtkdoc=disabled                  \
            -D tests=false                      \
            .. &&

ninja

If you removed the -D tests=false and want to run the tests, issue: ninja test.

Now, as the root user: 

ninja install

Command Explanations

--buildtype=release: Specify a buildtype suitable for stable releases of the package, as the default may produce unoptimized binaries.

-D system_bubblewrap=bwrap: Ensures the build system doesn't download Bubblewrap.

-D system_dbus_proxy=xdg-dbus-proxy: Ensures the build system doesn't download xdg-dbus-proxy.

-D gtkdoc=disabled: This parameter disables building the GTK-Doc API documentation. This is currently broken with gtk-doc-1.36.0, and causes the build to fail as a result.

-D tests=false: This parameter disables tests. Remove this parameter if you have socat installed.

Configuring Flatpak

Now that Flatpak is installed, you should add a repository/remote to install flatpaks from. Flathub is the most popular choice. You can do that with: 

flatpak remote-add flathub https://dl.flathub.org/repo/flathub.flatpakrepo

You can run it as a regular user or as root. If you run it as a regular user, polkit will ask for authentication. In this case, you should ensure polkit works first. If all went well, no error should be output. Then you will be able to install flatpaks from Flathub. All installed applications will be in /var/lib/flatpak/exports/bin. You can add that directory to your $PATH if you wish.

Contents

Installed Programs: flatpak, flatpak-bisect, flatpak-bwrap, flatpak-coredumpctl, flatpak-dbus-proxy, flatpak-oci-authenticator, flatpak-portal, flatpak-session-helper, flatpak-system-helper, flatpak-validate-icon, and revokefs-fuse
Installed Shell Script Triggers: desktop-database.trigger, gtk-icon-cache.trigger, and mime-database.trigger
Installed Libraries: libflatpak
Installed Directories: /usr/include/flatpak, /usr/lib/sysusers.d, and /usr/share/flatpak/triggers

Short Descriptions

desktop-database.trigger

is a trigger that updates a flatpak's application cache

flatpak

can run containerized and sandboxed applications

flatpak-bisect

can do a git-style bisect of a flatpak application

flatpak-bwrap

is used by flatpak to utilize Bubblewrap features

flatpak-coredumpctl

can debug an application in gdb that crashed inside flatpak.

flatpak-dbus-proxy

is used by flatpak to utilize xdg-dbus-proxy features

flatpak-oci-authenticator

is used by flatpak to athenticate with the Oracle OCI SDK

flatpak-portal

is used by flatpak to access the xdg-desktop-portal

flatpak-session-helper

is used by flatpak to help with session management

flatpak-system-helper

is usedi by flatpak to help with interacting with the underlying host system.

flatpak-validate-icon

is used by flatpak to validate icons

gtk-icon-cache.trigger

is a trigger that updates a flatpak's GTK icon cache

mime-database.trigger

is a trigger that updates a flatpak's MIME database cache

revokefs-fuse

makes a basepath visible at a given mountpoint

libflatpak

contains functions used by the Flatpak utilities


[3] While neither Flatpak or apps installed by it link to OpenGL on the system, each app will link against its own runtime/SDK of choice. Most of them use libglvnd. Running a libglvnd linked application on a Mesa OpenGL system is known to fail by failing to create an instance or context. If you haven't already, it's a good idea to switch to libglvnd to ensure compatibility.