# Introducing sessiond When I began using Linux on the desktop in ~2012, I experimented with the prevalent desktop environments (Gnome, KDE, etc.), but was quickly drawn into the realm of tiling window managers by their promise of increased productivity and customization. While I believe these promises were fulfilled, tiling window managers were not without a significant shortcoming: they are solely window managers, lacking the integrated suite of software and applications that put the environment in desktop environments. The most noticeable omission was proper *session management*, which facilitates, for instance: locking the screen or suspending the system after a period of inactivity. This was not a dealbreaker on a desktop computer, but using a laptop without these features felt like a dysfunctional hack. It would be quite a few more years of exploring the universe of tiling window managers before deciding to address this issue myself, and with the broad adoption of **systemd** by the larger Linux ecosystem, it was easier than ever. Enter: [sessiond](https://github.com/jcrd/sessiond), a standalone session manager for Linux. ## What does it do? **sessiond** is a daemon for **systemd**\-based Linux systems that interfaces with **systemd-logind** to provide the missing session management features to X11 window managers. Its primary responsibility is to monitor keyboard and mouse activity to determine when a session has become idle and to then act accordingly. It is capable of: * locking the screen when idle and before suspending the system * dimming the screen's backlight when idle * triggering **systemd** targets for use by the window manager or end user * optionally managing DPMS settings * controlling keyboard and monitor backlight brightness * controlling audio sink volume and mute state > The audio sink interface is new in version **0.6.0**. It also provides a D-Bus service so that it may be integrated with modern window managers. For example, a window manager can prevent idling when a media player is open by interacting with the D-Bus methods. It is designed to be zero-configuration, providing sensible defaults, but allows configuration if needed. See [here](https://jcrd.github.io/sessiond/configuration/) for additional details. ## How do I use it? **sessiond** requires a Linux system utilizing **systemd-logind**. It may be possible to use [elogind](https://github.com/elogind/elogind) but this has not been tested. > This brief tutorial assumes basic knowledge of ***systemd***\-based Linux systems and the command-line. ### Installation Currently, **sessiond** RPM packages are built for Fedora via [copr](https://copr.fedorainfracloud.org/coprs/jcrd/sessiond/) and installable with the following commands: ```shell dnf copr enable jcrd/sessiond dnf install sessiond ``` If you're using Arch Linux, **sessiond** is available via the [AUR](https://aur.archlinux.org/packages/sessiond) (thanks to [Denis Oster](https://github.com/denisoster))! Use your preferred AUR helper or install it with: ```shell git clone https://aur.archlinux.org/sessiond.git cd sessiond makepkg -si ``` I would like to see packages for other major distros in the future. Until **sessiond** achieves world domination, it is recommended to build from source by following [these instructions](https://jcrd.github.io/sessiond/building/). ### Setting up your window manager The intended way to use **sessiond** with your window manager of choice is to create a custom **systemd** service in the `~/.config/systemd/user` directory. For example, below is a `awesome.service` file that runs the [Awesome](https://awesomewm.org/) window manager: ```plaintext [Unit] Description=Awesome window manager Requires=sessiond-session.target After=sessiond.service PartOf=graphical-session.target [Service] ExecStart=/usr/bin/awesome [Install] Alias=window-manager.service ``` The options in the `[Unit]` section ensures your window manager is only running alongside the **sessiond** daemon. The `Alias=` option in the `[Install]` section lets **sessiond** know this service is the window manager so the session will be stopped when it exits. Next, enable the window manager service with `systemctl --user enable awesome.service`. Now, select the `sessiond session` entry via your display manager or set it as the default in its configuration file. For example, if using **lightdm**, set `user-session=sessiond` in `/etc/lightdm/lightdm.conf`. ### Locking the session **sessiond** wouldn't be of much use without a means of locking the screen. Create a service for your screen locker of choice in `~/.config/systemd/user`. For example, here is a `i3lock.service` that runs **i3lock** as the screen locker: ```plaintext [Unit] Description=Lock X session with i3lock PartOf=graphical-session.target [Service] ExecStart=/usr/bin/i3lock ExecStopPost=/usr/bin/sessionctl unlock [Install] WantedBy=graphical-lock.target ``` The `sessionctl unlock` command in `ExecStopPost` under the `[Service]` section notifies **sessiond** that the session has been unlocked when the service exits. Enable with `systemctl --user enable i3lock` so it's started upon triggering the `graphical-lock` target, which by default occurs when the session becomes inactive and before suspending the system. ### Other services Additional services (e.g. a compositor) can be started with the session by creating **systemd** service files in `~/.config/systemd/user` containing: ```plaintext [Unit] PartOf=graphical-session.target ``` and: ```plaintext [Install] WantedBy=graphical-session.target ``` Enable such services with `systemctl --user enable `. ### Inhibiting idling It's often desirable to prevent the session from idling while, for instance, watching a video. `sessiond-inhibit` comes to the rescue: ```shell sessiond-inhibit -y 'movie night' mpv ... ``` This can be automated if your window manager supports client rules and some level of scripting. ## More information For more information about **sessiond**, visit its [website](https://jcrd.github.io/sessiond/). You should now be equipped with sufficient knowledge to go forth and manage your sessions!