Sstrhsrtj

I have a simple need to run a systemd user service with access to all of the environment variables provided by the user DBus session. Here's my example unit:

[Unit]

Description=Environment Demo



[Service]

Type=simple

Environment=DISPLAY=:0

ExecStart=/bin/bash -c 'env > shell.env.sh'

Restart=on-failure

RestartSec=5s

StandardOutput=journal

StandardError=journal



[Install]

WantedBy=default.target

The keys exported are:

_

DISPLAY

HOME

LANG

LOGNAME

MANAGERPID

PATH

PWD

SHELL

SHLVL

USER

XDG_RUNTIME_DIR

This is a far cry from the full list of environment variables present if I launch a desktop application from my tray or from my launcher (I'm on elementary OS Loki aka Ubuntu 16.04 xenial). If I launch my terminal emulator (pantheon-terminal) and I get a sorted list of my environment variables, I get the following:

_

DBUS_SESSION_BUS_ADDRESS

DEFAULTS_PATH

DESKTOP_SESSION

DISPLAY

EDITOR

GDM_LANG

GDMSESSION

GIO_LAUNCHED_DESKTOP_FILE

GIO_LAUNCHED_DESKTOP_FILE_PID

GNOME_DESKTOP_SESSION_ID

GPG_TTY

GSETTINGS_SCHEMA_DIR

GTK_CSD

GTK_MODULES

HOME

LANG

LANGUAGE

LESSCLOSE

LESSOPEN

LOGNAME

LS_COLORS

MANDATORY_PATH

PANTHEON_TERMINAL_ID

PATH

PROMPT_COMMAND

PWD

QT_ACCESSIBILITY

QT_IM_MODULE

QT_LINUX_ACCESSIBILITY_ALWAYS_ON

QT_STYLE_OVERRIDE

SESSION_MANAGER

SHELL

SHLVL

SSH_AGENT_PID

SSH_AUTH_SOCK

TERM

USER

VTE_VERSION

XAUTHORITY

XDG_CONFIG_DIRS

XDG_CURRENT_DESKTOP

XDG_DATA_DIRS

XDG_GREETER_DATA_DIR

XDG_MENU_PREFIX

XDG_RUNTIME_DIR

XDG_SEAT

XDG_SEAT_PATH

XDG_SESSION_DESKTOP

XDG_SESSION_ID

XDG_SESSION_PATH

XDG_SESSION_TYPE

XDG_VTNR

XMODIFIERS

To make things more clear:

diff --git a/systemd-user.env.txt b/pantheon-terminal.env.txt

index c684056..f6d0685 100644

--- a/systemd-user.env.txt

+++ b/pantheon-terminal.env.txt

@@ -1,12 +1,54 @@

 _

+DBUS_SESSION_BUS_ADDRESS

+DEFAULTS_PATH

+DESKTOP_SESSION

 DISPLAY

+EDITOR

+GDM_LANG

+GDMSESSION

+GIO_LAUNCHED_DESKTOP_FILE

+GIO_LAUNCHED_DESKTOP_FILE_PID

+GNOME_DESKTOP_SESSION_ID

+GPG_TTY

+GSETTINGS_SCHEMA_DIR

+GTK_CSD

+GTK_MODULES

 HOME

 LANG

+LANGUAGE

+LESSCLOSE

+LESSOPEN

 LOGNAME

-MANAGERPID

+LS_COLORS

+MANDATORY_PATH

+PANTHEON_TERMINAL_ID

 PATH

+PROMPT_COMMAND

 PWD

+QT_ACCESSIBILITY

+QT_IM_MODULE

+QT_LINUX_ACCESSIBILITY_ALWAYS_ON

+QT_STYLE_OVERRIDE

+SESSION_MANAGER

 SHELL

 SHLVL

+SSH_AGENT_PID

+SSH_AUTH_SOCK

+TERM

 USER

+VTE_VERSION

+XAUTHORITY

+XDG_CONFIG_DIRS

+XDG_CURRENT_DESKTOP

+XDG_DATA_DIRS

+XDG_GREETER_DATA_DIR

+XDG_MENU_PREFIX

 XDG_RUNTIME_DIR

+XDG_SEAT

+XDG_SEAT_PATH

+XDG_SESSION_DESKTOP

+XDG_SESSION_ID

+XDG_SESSION_PATH

+XDG_SESSION_TYPE

+XDG_VTNR

+XMODIFIERS

There are somewhere around 30 more environment variables when starting something this way.

My use case is this: I want to be able to start processes with a full environment like in the context of launching my terminal application.

How can I expose a full(er) environment to my systemd user daemons?

You may find some help in the ArchLinux wiki page which discusses setting the environment for user Units. In particular,

systemctl --user import-environment 

will export all the current environment variables into your systemd user environment. You can provide an explicit list of variables instead. You can check by running

systemctl --user show-environment

before and after. There is also

systemctl --user set-environment MYVAR=myvalue ...

systemctl --user unset-environment MYVAR ...

See the systemctl man page.
The wiki also mentions a dbus specific alternative with which I had less success:

dbus-update-activation-environment --systemd --all

My solution takes into account @meuh's solution above and some digging.

Step one is to create a dummy user unit called dbus-environment.service:

[Unit]

Description=Environment Imported Target



[Service]

Type=oneshot

RemainAfterExit=true

ExecStart=/bin/true

Next step is to create a Bash script:

#!/bin/bash



systemctl --user import-environment

systemctl --user start dbus-environment.service

Next, add this script to your window manager's startup applications which are guaranteed to run within the DBUS session and the window manager, X, etc.

On session login, the script will be called, importing everything into the systemd user daemon.

Next, for all units depending on these environment variables, simply have them depend on dbus-environment.service:

[Unit]

Description=Duplicity Backup Service

Requires=dbus-environment.service

After=dbus-environment.service



[Service]

Type=oneshot

ExecStart=/home/naftuli/.local/bin/duply home backup

At this point, when this service starts, it is guaranteed to have the environment imported. Perhaps I should be using a target rather than a service, but that exercise will have to wait.

@Naftuli:
Would it not have been better to instead use something like this in all your services unit files?

ExecStartPre=usrbinsh -c "systemctl --user import-environment"