e1e64e4d25
Sometimes we're not able to access the `xa.cache` data that's usually in
the summary and ostree-metadata, such as when the remote is a USB drive
that had `ostree summary -u` run on it. In that case, we don't want
flatpak_remote_ref_new() to fail, because the FlatpakRemoteRef instance
might still be useful enough without the metadata, such as in
flatpak_installation_list_remote_refs_sync. So this commit makes the
metadata property of FlatpakRemoteRef nullable which has the effect of
making the test_list_refs_in_remote() test pass with P2P enabled.
The metadata property wasn't added to FlatpakRemoteRef until commit
c33f842b7 so presumably no one is depending on it.
Closes: #1600
Approved by: alexlarsson
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 on Freenode and on the mailing list.
Read documentation for the flatpak commandline tools and for the libflatpak library API.
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
- Update 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
./configure [args]
make
make install
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 installed
flatpaks. 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-installation, called flatpak-system-helper. This is dbus
activated (on the system-bus) and if you install in a non-standard
location it is likely that this will not be found by dbus and
policykit. However, if the system installation is synchronized,
you can often use the system installed helper instead - at least
if the two versions are close in versions.