The session slice and the app and background slices are special slices defined by
https://systemd.io/DESKTOP_ENVIRONMENTS/, where:
session.slice: Contains only processes essential to run the user’s graphical session
app.slice: Contains all normal applications that the user is running
This allows users or sysadmins to control resource allocation depending on the type
of the service.
Since v249 (23dce98e89)
systemd puts user services into the app slice by default so dbus needs to manually state
that it belongs in the session slice.
Like --fork and --nofork, these override what the configuration says.
Use --syslog-only to force the systemd services to log to the Journal
(via syslog, which means we see the severity metadata) instead of
testing sd_booted() in the configuration implementation.
Signed-off-by: Simon McVittie <smcv@debian.org>
We install the symlink to enable dbus.socket statically, so it doesn't
make much sense to invoke `systemctl enable` on it; and
dbus.service should normally be started by socket activation
(or possibly an explicit dependency) rather than manually.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=92402
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Lennart Poettering
The socket path used here, $XDG_RUNTIME_DIR/bus, does not match
what was used in user-session-units, but is what Lennart recommended
on fd.o #61303, and is also what kdbus will use for its bus proxy.
Installation of these units switches D-Bus to a different model of
the system: instead of considering each login session (approximately,
each password typed in) to be its own session, the user-session model
is that all concurrent logins by the same user form one large session.
This allows the same bus to be shared by a graphical session, cron jobs,
tty/ssh sessions, screen/tmux sessions and so on.
Because this is a different world-view, it is compile-time optional:
OS builders can choose which world their OS will live in. The default
is still the login-session model used in earlier D-Bus releases,
but might change to the user-session model in future. Explicit
configuration is recommended.
In OSs that support both models (either for sysadmin flexibility or as
a transitional measure), the OS builder should enable the user bus
units, but split them off into a dpkg binary package, RPM subpackage etc.;
the sysadmin can choose whether to enable the user-session model by
choosing whether to install that package.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=61301
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
