7f3556d92c
Currently the xa.noenumerate option on a remote is documented as causing the remote not to be used when presenting available apps/runtimes or when searching for dependencies. The idea is that the remote is only used for providing updates for things installed from it, and this functionality is used when creating an origin remote for something installed via a flatpakref file. However, the implementation of this in flatpak_dir_list_remote_refs() is buggy. It returns an empty set of refs even if something is both locally installed and available from the remote. This is because it is using hash table comparisons of FlatpkDecomposed objects (via flatpak_decomposed_hash()) which take into account both the ref (or refspec) and the collection ID, and the local refs' FlatpakDecomposed objects are created from a refspec whereas the remote refs' FlatpakDecomposed objects are created from a ref alone. We could fix this by having them both use refspecs, but it is better to use a collection-ref tuple for the following reasons: (1) Changing flatpak_dir_list_all_remote_refs() to use a refspec to create the FlatpakDecomposed objects would be a breaking change for the other users of that function. (2) Both the local and remote refs are from the same remote so we don't need to use the remote name to disambiguate them, even if no collection ID is configured. (3) The whole point of collection IDs is to make refs uniquely identifiable, so we're using them for the intended purpose. In addition to fixing this bug, this commit adds a unit test in testlibrary.c so it stays fixed.
Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux.
See https://flatpak.org/ for more information.
Community discussion happens in #flatpak:matrix.org, on the mailing list, and on the Flathub Discourse.
Read documentation for Flatpak here.
Contributing
Flatpak welcomes contributions from anyone! Here are some ways you can help:
- Fix one of the issues and submit a PR
- Update flatpak's translations and submit a PR
- Improve flatpak's documentation, hosted at http://docs.flatpak.org and developed over in flatpak-docs
- Find a bug and submit a detailed report including your OS, flatpak version, and the steps to reproduce
- Add your favorite application to Flathub by writing a flatpak-builder manifest and submitting it
- Improve the Flatpak support in your favorite Linux distribution
Hacking
Flatpak uses a traditional autoconf-style build mechanism. To build just do
./autogen.sh
./configure [args]
make
make install
To automatically install dependencies on apt-based distributions you can try
running apt build-dep flatpak and on dnf ones try dnf builddep flatpak.
Dependencies you will need include: autoconf, automake, libtool, bison,
gettext, gtk-doc, gobject-introspection, libcap, libarchive, libxml2, libsoup,
gpgme, polkit, libXau, ostree, json-glib, appstream, libseccomp (or their devel
packages).
Most configure arguments are documented in ./configure --help. However,
there are some options that are a bit more complicated.
Flatpak relies on a project called Bubblewrap for the
low-level sandboxing. By default, an in-tree copy of this is built
(distributed in the tarball or using git submodules in the git
tree). This will build a helper called flatpak-bwrap. If your system
has a recent enough version of Bubblewrap already, you can use
--with-system-bubblewrap to use that instead.
Bubblewrap can run in two modes, either using unprivileged user
namespaces or setuid mode. This requires that the kernel supports this,
which some distributions disable. For instance, Debian and Arch
(linux kernel v4.14.5
or later), support user namespaces with the kernel.unprivileged_userns_clone
sysctl enabled.
If unprivileged user namespaces are not available, then Bubblewrap must be built as setuid root. This is believed to be safe, as it is designed to do this. Any build of Bubblewrap supports both unprivileged and setuid mode, you just need to set the setuid bit for it to change mode.
However, this does complicate the installation a bit. If you pass
--with-priv-mode=setuid to configure (of Flatpak or Bubblewrap) then
make install will try to set the setuid bit. However that means you
have to run make install as root. Alternatively, you can pass
--enable-sudo to configure and it will call sudo when setting the
setuid bit. Alternatively you can enable setuid completely outside of
the installation, which is common for example when packaging Bubblewrap
in a .deb or .rpm.
There are some complications when building Flatpak to a different
prefix than the system-installed version. First of all, the newly
built Flatpak will look for system-installed flatpaks in
$PREFIX/var/lib/flatpak, which will not match existing installations.
You can use --with-system-install-dir=/var/lib/flatpak to make both
installations use the same location.
Secondly, Flatpak ships with a root-privileged PolicyKit helper for
system-wide installation, called flatpak-system-helper. It is D-Bus
activated (on the system bus) and if you install in a non-standard
location it is likely that D-Bus will not find it and PolicyKit
integration will not work. However, if the system installation is
synchronized, you can often use the system installed helper instead—
at least if the two versions are close enough.
This repository
The Flatpak project consists of multiple pieces, and it can be a bit challenging to find your way around at first. Here is a quick intro to each of the important subdirectories:
app: the commandline client. Each command has aflatpak-builtins-source filecommon: contains the library, libflatpak. It also contains various pieces of code that are shared between the library, the client and the services. Non-public code can be recognized by having a-private.hheader file.completion: commandline auto completion supportdata: D-Bus interface definition files and GVariant schemasdoc: The sources for the documentation, both man pages and library documentationicon-validator: A small utility that is used to validate iconsoci-authenticator: service used for authenticating the user for installing from oci remotes (e.g. for paid apps)po: translationsportal: The Flatpak portal service, which lets sandboxed apps request the creation of new sandboxesrevokefs: A FUSE filesystem that is used to transfer files downloaded by the user to the system-helper without copyingsession-helper: The flatpak-session-helper service, which provides various helpers for the sandbox setup at runtimetests: The testsuitesubprojects/bubblewrap: Flatpak's unprivileged sandboxing tool which is developed separately and exists here as a submodulesubprojects/libglnx: a small utility library for projects that use GLib on Linux, as a submodulesubprojects/dbus-proxy: a filtering proxy for D-Bus connections, as a submodulesubprojects/variant-schema-compiler: a tool for generating code to efficiently access data encoded using GVariant, as a submodulesystem-helper: The flatpak-system-helper service, which runs as root on the system bus and allows non-root users to modify system installations
Related Projects
Here are some notable projects in the Flatpak ecosystem:
- Flatseal: An app for managing permissions of Flatpak apps without using the CLI
- Souk: A Flatpak-only app store
- Flat-manager: A tool for managing Flatpak repositories