[systemd-devel] Standardizing names for graphical session units

[Simon McVittie]

On 04/07/16 21:01, Martin Pitt wrote:
> A session type like "GNOME" or "KDE" then defines which top-level
> servcies it wants.

Could this be done by having the .desktop file in /usr/share/xsessions
or /usr/share/wayland-sessions start an appropriate systemd user unit
directly, and wait for it to terminate?

> Ideally we could hook the startup of graphical.slice into the system
> logind scope; but as the user systemd does not "see" the
> systemd users, this isn't possible. So for now pretty much the only
> way is to go via an /X11/xinit/xinitrc.d (Fedora) or
> /etc/X11/Xsession.d/ (Debian) script

These scripts are a necessary evil for X11, but in the Wayland future,
the plan (at least in GNOME) seems to be for them not to be replicated;
if gdm is told to launch a session from /usr/share/wayland-sessions, it
doesn't execute X11 startup script snippets. (It does have a
gdm-specific way to set environment variables, and I'm planning to
extend pam_env to support systemd-style .d drop-in directories to
generalize that.) A more declarative session startup seems like a better
session startup.

I'm not sure what you do for Mir in Ubuntu, but I'd advocate a similar
approach - sourcing a couple of dozen Turing-complete shell script
fragments during session startup makes it rather difficult to reason about.

    S

-- 
Simon McVittie
Collabora Ltd. <http://www.collabora.com/>