# systemd/User

Related articles

- systemd
- Automatic login to virtual console
- Start X at Login

systemd offers users the ability to run an instance of systemd to manage their session and services. This allows users to start, stop, enable, and disable units found within certain directories when systemd is run by the user. This is convenient for daemons and other services that are commonly run as a user other than root or a special user, such as mpd.

## Setup since systemd 206

Note: User sessions are in development, have some missing features and are not yet supported upstream. See [1] and [2] for some details on the current state of affairs.

Since version 206, the mechanism for systemd user instances has changed. Now the `pam_systemd.so` module launches a user instance by default on the first login of an user, by starting `user@.service`. In its current state there are some differences with respect to previous systemd versions, that one must be aware of:

- The `systemd --user` instance runs outside of any user session. This is ok for running, say `mpd`, but may be annoying if one tries to start a window manager from the systemd user instance. Then polkit will prevent from mounting usb's, rebooting, etc. as an unprivileged user, because the window manager is running outside of the active session.
- The units in the user instance do not inherit any environment, so it must be set manually.
- `user-session@.service` from user-session-units is obsolete now.

Steps to use user instance units:

1. Make sure the systemd user instance starts properly. You can check if it is there with

    systemctl --user status

Since systemd 206 there should be a systemd user instance running by default, which is started in the `pam_systemd.so` pam module for the first login of a user.
Note: `/etc/pam.d/system-login` must start `pam_systemd.so`: it should contain `-session optional pam_systemd.so`; check if a .pacnew file exists.

2. Add the environment variables you need in a config file for `user@.service`. For example:

    /etc/systemd/system/user@.service.d/environment.conf

    [Service]
    Environment=DISPLAY=:0
    Environment=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/%I/bus

Note: Since systemd 209 we need to set `DBUS_SESSION_BUS_ADDRESS` manually. On systemd 208 this variable was set by `user@.service`, but not anymore since 209. The reason seems to be that once the transition to kdbus is done, this variable will be set by pam_systemd.so.

3. Put your user units in `~/.config/systemd/user`. When the user instance starts, it launches the default target at `~/.config/systemd/user/default.target`. After that, you can manage your user units with `systemctl --user`.

### D-Bus

To use dbus in user units, create the following files:

    /etc/systemd/user/dbus.socket

    [Unit]
    Description=D-Bus Message Bus Socket
    Before=sockets.target

    [Socket]
    ListenStream=/run/user/%U/bus

    [Install]
    WantedBy=default.target

    /etc/systemd/user/dbus.service

    [Unit]
    Description=D-Bus Message Bus
    Requires=dbus.socket

    [Service]
    ExecStart=/usr/bin/dbus-daemon --session --address=systemd: --nofork --nopidfile --systemd-activation
    ExecReload=/usr/bin/dbus-send --print-reply --session --type=method_call --dest=org.freedesktop.DBus / org.freedesktop.DBus.ReloadConfig

Note: Since systemd 209 `systemd-run` seems to use a hardcoded bus socket, ignoring `DBUS_SESSION_BUS_ADDRESS`. Using the path `/run/user/%U/bus` for the user dbus socket solves the issue. This is the path kdbus will be using.

Activate the socket by running

    # systemctl --global enable dbus.socket

### Automatic login into Xorg without display manager

You need to have #D-Bus correctly set up and xlogin-git installed.

Set up your xinitrc from the skeleton, so that it will source the files in `/etc/X11/xinit/xinitrc.d/`. Running your `~/.xinitrc` should not return, so either have `wait` as the last command, or add `exec` to the last command that will be called and which should not return (your window manager, for instance).

The session will use its own dbus daemon, but various systemd utilities need the `dbus.service` instance. Possible solution to this is to create aliases for such commands:

    ~/.bashrc

    for sd_cmd in systemctl systemd-analyze systemd-run; do
        alias $sd_cmd='DBUS_SESSION_BUS_ADDRESS="unix:path=$XDG_RUNTIME_DIR/dbus/user_bus_socket" '$sd_cmd
    done

Finally, enable (as root) the xlogin service for automatic login at boot:

    # systemctl enable xlogin@username

The user session lives entirely inside a systemd scope and everything in the user session should work just fine.

### Automatic start-up of systemd user instances

The systemd user instance is by default run after the first login of a user, but sometimes it may be useful to start it right after boot. Lingering is used to spawn the systemd user instance at boot and keep it running after logouts.

Warning: systemd services are not sessions, they run outside of logind. Do not use lingering to enable automatic login as it will break the session.

Use the following command to enable lingering for specific user:

    # loginctl enable-linger username

## Setup

### Using /usr/lib/systemd/systemd --user To Manage Your Session

Systemd has many amazing features, one of which is the ability to track programs using cgroups (by running `systemctl status`). While awesome for a pid 1 process to do, it is also extremely useful for users, and having it set up and initialize user programs, all the while tracking what is in each cgroup is even more amazing.

All of your systemd user units will go to `$HOME/.config/systemd/user`. These units take precedence over units in other systemd unit directories.

There are two packages you need to get this working, both currently available from the AUR: systemd-xorg-launch-helper-git and optionally, systemd-user-session-units-git if you want to have autologin working.

Next is setting up your targets. You should set up two, one for window manager and another as a default target. The window manager target should be populated like so:

    $HOME/.config/systemd/user/wm.target

    [Unit]
    Description=Window manager target
    Wants=xorg.target
    Wants=mystuff.target
    Requires=dbus.socket
    AllowIsolate=true

    [Install]
    Alias=default.target

This will be the target for your graphical interface.

Put together a second target called `mystuff.target`. All services but your window manager should contain a `WantedBy` line, under `[Install]`, pointing at this unit.

    $HOME/.config/systemd/user/mystuff.target

    [Unit]
    Description=Xinitrc Stuff
    Wants=wm.target

    [Install]
    Alias=default.target

Create a symbolic link from this unit to `default.target`. When you start `/usr/lib/systemd/systemd --user`, it will start this target.

Next you need to begin writing services. First you should throw together a service for your window manager:

    $HOME/.config/systemd/user/YOUR_WM.service

    [Unit]
    Description=your window manager service
    Before=mystuff.target
    After=xorg.target
    Requires=xorg.target

    [Service]
    #Environment=PATH=uncomment:to:override:your:PATH
    ExecStart=/full/path/to/wm/executable
    Restart=always
    RestartSec=10

    [Install]
    WantedBy=wm.target

Note: The `[Install]` section includes a 'WantedBy' part. When using `systemctl --user enable` it will link this as `$HOME/.config/systemd/user/wm.target.wants/YOUR_WM.service`, allowing it to be started at login. Is recommended enabling this service, not linking it manually.

You can fill your user unit directory with a plethora of services, including ones for mpd, gpg-agent, offlineimap, parcellite, pulse, tmux, urxvtd, xbindkeys and xmodmap to name a few.

To exit your session, use `systemctl --user exit`.

### Auto-login

If you want to have systemd automatically log you in on boot, then you can use the unit in user-session-units to do so. Enabling a screen locker for will stop someone from booting your computer into a nice, logged in session. Add this line to `/etc/pam.d/login` and `/etc/pam.d/system-auth`:

    session    required    pam_systemd.so

Because `user-session@.service` starts on tty1, you will need to add `Conflicts=getty@tty1.service` to the service file, if it doesn't exist already. Alternately, you can have it run on tty7 instead by modifying `TTYPath` accordingly as well as the `ExecStart` line in `xorg.service` (`cp /usr/lib/systemd/user/xorg.service /etc/systemd/user/` and make the modifications there).

Once this is done, `systemctl --user enable` `YOUR_WM.service`

Note: One must be careful with tty's to keep the systemd session active. Systemd sets a session as inactive when the active tty is different from the one that the login took place. This means that the X server must be run in the same tty as the login in `user-session@.service`. If the tty in `TTYPath` does not match the one xorg is launched in, the systemd session will be inactive from the point of view of your X applications, and you will not be able to mount USB drives, for instance.

One of the most important things you can add to the service files you will be writing is the use of `Before=` and `After=` in the `[Unit]` section. These two parts will determine the order things are started. Say you have a graphical application you want to start on boot, you would put `After=xorg.target` into your unit. Say you start ncmpcpp, which requires mpd to start, you can put `After=mpd.service` into your ncmpcpp unit. You will eventually figure out exactly how this needs to go either from experience or from reading the systemd manual pages. Starting with systemd.unit(5) is a good idea.

### Other use cases

#### Persistent terminal multiplexer

You may wish your user session to default to running a terminal multiplexer, such as GNU Screen or Tmux, in the background rather than logging you into a window manager session. Separating login from X login is most likely only useful for those who boot to a TTY instead of to a display manager (in which case you can simply bundle everything you start in with myStuff.target).

To create this type of user session, procede as above, but instead of creating wm.target, create multiplexer.target:

    [Unit]
    Description=Terminal multiplexer
    Documentation=info:screen man:screen(1) man:tmux(1)
    After=cruft.target
    Wants=cruft.target

    [Install]
    Alias=default.target

`cruft.target`, like `mystuff.target` above, should start anything you think should run before tmux or screen starts (or which you want started at boot regardless of timing), such as a GnuPG daemon session.

You then need to create a service for your multiplexer session. Here is a sample service, using tmux as an example and sourcing a gpg-agent session which wrote its information to `/tmp/gpg-agent-info`. This sample session, when you start X, will also be able to run X programs, since DISPLAY is set.

    [Unit]
    Description=tmux: A terminal multiplixer Documentation=man:tmux(1)
    After=gpg-agent.service
    Wants=gpg-agent.service

    [Service]
    Type=forking
    ExecStart=/usr/bin/tmux start
    ExecStop=/usr/bin/tmux kill-server
    Environment=DISPLAY=:0
    EnvironmentFile=/tmp/gpg-agent-info

    [Install]
    WantedBy=multiplexer.target

Once this is done, `systemctl --user enable` `tmux.service`, `multiplexer.target` and any services you created to be run by `cruft.target` and you should be set to go! Activated `user-session@.service` as described above, but be sure to remove the `Conflicts=getty@tty1.service` from `user-session@.service`, since your user session will not be taking over a TTY. Congratulations! You have a running terminal multiplexer and some other useful programs ready to start at boot!

##### Starting X

You have probably noticed that, since the terminal multiplexer is now `default.target`, X will not start automatically at boot. To start X, proceed as above, but do not activate or manually link to `default.target` `wm.target`. Instead, assuming you are booting to a terminal, we will simply be using a hack-ish workaround and masking `/usr/bin/startx` with a shell alias:

    alias startx='systemctl --user start wm.target'

## User Services

Users may now interact with units located in the following directories just as they would with system services (ordered by ascending precedence):

- `/usr/lib/systemd/user/`
- `/etc/systemd/user/`
- `~/.config/systemd/user/`

To control the systemd instance, the user must use the command `systemctl --user`.

### Installed by packages

A unit installed by a package that is meant to be run by a systemd user instance should install the unit to `/usr/lib/systemd/user/`. The system adminstration can then modify the unit by copying it to `/etc/systemd/user/`. A user can then modify the unit by copying it to `~/.config/systemd/user/`.

### Example

The following is an example of a user version of the mpd service.

    mpd.service

    [Unit]
    Description=Music Player Daemon

    [Service]
    ExecStart=/usr/bin/mpd --no-daemon

    [Install]
    WantedBy=default.target

### Example with variables

The following is an example of a user version of `sickbeard.service`, which takes into account variable home directories where SickBeard can find certain files:

    sickbeard.service

    [Unit]
    Description=SickBeard Daemon

    [Service]
    ExecStart=/usr/bin/env python2 /opt/sickbeard/SickBeard.py --config %h/.sickbeard/config.ini --datadir %h/.sickbeard

    [Install]
    WantedBy=default.target

As detailed in `man systemd.unit`, the `%h` variable is replaced by the home directory of the user running the service. There are other variables that can be taken into account in the systemd manpages.

### Note about X applications

Most X apps need a `DISPLAY` variable to run (so it's likely the first reason why your service files aren't starting), so you have to make sure to include it:

    $HOME/.config/systemd/user/parcellite.service

    [Unit]
    Description=Parcellite clipboard manager

    [Service]
    ExecStart=/usr/bin/parcellite
    Environment=DISPLAY=:0 # <= !

    [Install]
    WantedBy=mystuff.target

A simpler way, if using user-session-units, is to define it in `user-session@yourloginname.service` so it's inherited. Add `Environment=DISPLAY=:0` to the `[Service]` section. Another helpful environment variable to set here is `SHELL`.

A cleaner way though, is to not hard code the DISPLAY environment variable (specially if you run more than on display):

    $HOME/.config/systemd/user/x-app-template@.service

    [Unit]
    Description=Your amazing and original description

    [Service]
    ExecStart=/full/path/to/the/app
    Environment=DISPLAY=%i # <= !

    [Install]
    WantedBy=mystuff.target

Then you can run it with:

    systemctl --user {start|enable} x-app@your-desired-display.service # <= :0 in most cases

Some X apps may not start up because the display socket is not available yet. This can be fixed by adding something like

    $HOME/.config/systemd/user/x-app-template@.service

    [Unit]
    After=xorg.target
    Requires=xorg.target

    ...

to your units (the `xorg.target` is part of xorg-launch-helper).

## See also

- KaiSforza's Bitbucket wiki
- Zoqaeski's units on GitHub
- Collection of useful systemd user units
- More systemd user units
- Arch forum thread about changes in systemd 206 user instances

Categories:

- Daemons and system services
- Boot process