polkit is a software framework to handle privileges of processes. In LXQt it is e. g. used to extend the privileges of the GUI tools of lxqt-admin. These are launched by a regular user. But in order to apply the settings that can be adjusted root privileges are needed and acquired via polkit.

Among the various components of polkit the authentication agent is the one to query the user for credentials and hence comes with its own GUI like this one of lxqt-policykit.

While there's only a single implementation of all other polkit components there are various different authentication agents provided by the various desktop environments. Normally these can be used interchangeably, that is lxqt-policykit can be used in an LXDE session or lxpolkit, the authentication agent of LXDE, can be used in an Xfce session. Normally it's better to use the implementation provided by a distinct desktop environment as it integrates better, though.

Technically, lxqt-policykit is just a single binary lxqt-policykit-agent which has to be running all over the LXQt sessions and is therefor launched as so-called LXQt Module, see Configuration.

Note that the naming lxqt-policykit is strictly speaking an anachronism. It refers to Policykit which was the predecessor of polkit. The name wasn't changed when Policykit was replaced by polkit as both provide roughly the same features albeit they are technically different.

Installing

Compiling sources

Runtime dependencies are liblxqt and its dependency libqtxdg as well as polkit-qt5, to build Git and CMake are needed in addition.
By default lxqt-policykit is pulling translations from repository translations at compile time, see file README.md of the latter.

To compile, run cmake, make and make install. cmake can be invoked in an out of source build directory and will normally need variable -DCMAKE_INSTALL_PREFIX=/usr. make install can be invoked with DESTDIR=<some path>.

Binary packages

Arch Linux

The latest release is provided by package lxqt-policykit in repository community, the actual master checkout can be compiled by packages lxqt-policykit-git from the AUR.

Debian

Package lxqt-policykit is available in the official repositories as of Debian stretch. For now it is comprising the translations as well but these will probably be outsourced in package lxqt-policykit-l10n one day.

Fedora

Package lxqt-policykit is available as of Fedora 22.

openSUSE

Package lxqt-policykit is providing the binary, lxqt-policykit-lang the translations. Both are available as of openSUSE Leap 42.1.

Configuration

As mentioned in section Overview binary lxqt-policykit-agent is started as LXQt Module, which is a particular way of LXQt to launch binaries at the beginning of an LXQt session and keep them running all the time.
This is handled by desktop entry file /etc/xdg/autostart/lxqt-policykit-agent.desktop. It belongs to lxqt-common and is featuring key OnlyShowIn=LXQt; restricting it to LXQt sessions. So no further action has to be taken as far as LXQt is concerned. In order to use lxqt-policykit in other sessions the key has to be modified accordingly and/or removed, optionally after copying the file to a user specific directory, normally ~/.config/autostart/.

Usage

From a user's point of view the usage is limited to interacting with the GUI as seen above.