If the directory referred to by ReadWritePaths= does not exist, the
service fails to start:
systemd[1]: Starting Fingerprint Authentication Daemon...
systemd[9736]: fprintd.service: Failed to set up mount namespacing: No such file or directory
systemd[9736]: fprintd.service: Failed at step NAMESPACE spawning /usr/lib/fprintd/fprintd: No such file or directory
systemd[1]: fprintd.service: Main process exited, code=exited, status=226/NAMESPACE
systemd[1]: fprintd.service: Failed with result 'exit-code'.
systemd[1]: Failed to start Fingerprint Authentication Daemon.
This may happen when booting with an empty /var filesystem.
For a system service, "StateDirectory=fprint" causes /var/lib/fprint and
any parent directories to be created if missing (with mode 0755 by
default, owned by the user and group of the service, which in this case
is root). In combination with ProtectSystem=strict, this state
directory will be mounted read-write. StateDirectory was introduced in
systemd 235, so require at least this version.
The /var/lib prefix is hardcoded in systemd. (Since systemd 240, the
full path(s) to StateDirectory are provided as $STATE_DIRECTORY, but
since it is always /var/lib, we continue to just hardcode that path.)
On non-systemd systems, since fprintd runs as root with no confinement,
it can create its state directory as needed (with g_mkdir_with_parents()
in file_storage_print_data_save()).
--localstatedir (and --prefix) will now be ignored in favour of this
hardcoded path. This is in preparation for a change to use systemd's
StateDirectory feature.
Give read-write access to USB devices in /dev, and the location of the
fingerprints, access to Unix sockets for D-Bus and
close everything else down.
See systemd.exec(5) for details about the options.
Add PolicyKit checks to all the public functions, grouped
in 2 main groups: Verify and Enroll
By default, only the user is able to enroll new fingers,
or verify themselves.
You need to be allowed at least one of those 2 actions
to be allowed to claim or release the device.
We also add a new SetUsername function, for administration
functions. Users will need to be authenticate as admins to
be allowed to change the username on which the actions will
be taken. Any prints loaded before the change of username will
be unloaded.
