Re: Question about propagation of INVOCATION_ID and JOURNAL_STREAM env variables in Desktop Environments

[Lennart Poettering <lennart@xxxxxxxxxxxxxx>]

On Mi, 22.05.24 17:13, Nop (ctxnop@xxxxxxxxx) wrote:

> Hello folks,
> I have a question about what you guys considers to be the right/expect way.
>
> I read documentation a bit about INVOCATION_ID and JOURNAL_STREAM and, to
> me, it feels like those two variables should not be propagated from
> DE.

What precisely do you mean by "DE"? Most desktop environments these
days use systemd as service manager for per-user services too, and
hence they'll get a properly initialized INVOCATION_ID set for each
service.

If you use a traditional DE that does not use systemd, then you
shouldn't have set INVOCATION_ID since you are invoked from a PAM
session, not from a system service, hence nothing to clean up.

Hence, I am not really grokking your question. Either you buy into
systemd or you don't. If you do you should be in the clear and have
valid invocation IDs, and if you don't you should also be clear and
not have the variable set at all. So all should be good?

> I mean, if I start KDE Plasma, for example, using systemd, it will receive
> an $INVOCATION_ID. Now I start any application by clicking around, it will
> inherit and get the very same $INVOCATION_ID.

Applications are usually started via systemd too, so no?

> If the application happen to be konsole or kitty (terminal
> emulator), it still inherit the variables, so that any command run
> inside this terminal emulator also inherit from it.  Feels really
> weird to me, no?

Graphical terminal apps should really not let INVOCATION_ID leak into
their sub-sessions, they are kinda their own thing then.

> I checked a bit what gnome is doing and it confused me even more: all
> applications inherit the variables but the 'gnome-terminal' filters out few
> variables (including those two) so that commands don't have it:
> https://gitlab.gnome.org/GNOME/gnome-terminal/-/blob/master/src/terminal-client-utils.cc#L227

Seems it's doing things right then.

> What is your take on this? At which level the filter should occurs if it
> should even occurs at all?

When you open a new "sub-session" or so, and fork processes off down
the tree, then it might make sense to unset these env vars for them.

Lennart

--
Lennart Poettering, Berlin