On 15 Jun 2024, at 00:18, Grant Taylor via TUHS
<tuhs(a)tuhs.org> wrote:
It's my understanding that systemd as a service lifecycle manager is starting to
take on some aspects of what cluster service managers used to do.
I think it goes beyond this, and that systemd is just a convenient focus point for folks
to push back against a wider set of changes.
My usual example here is PolKit and polkitd. In this latest systemd release, for example,
it seems the new systemd-run0 command (replacing sudo or su), starts a privileged process
by checking permissions with polkitd over DBus, and then uses systemd to actually fork and
setup the “child”.
This is a fairly distinctive departure from how Unix works: over the last decade, Linux
has increasingly moved away from being Unix, and I think this is why people find systemd
so confronting. And there’s more to come, eg. varlink.
I’m sure systemd, polkitd and their ilk address real needs. But the solution isn’t (in my
view) Unix-like, and those for whom Linux is a convenient Unix are disappointed (to put it
mildly).
The world is no longer a PDP-11 or a Vax or a SPARCstation. USB in particular introduced
a lot more dynamism to the Unix device model, and started us down this path of devfs,
DBus, systemd, etc. Users reasonably want things to work, and Red Hat wants to satisfy
those users, and they’ve chosen this way to do it. Unfortunately, there’s been no real
competition: this goes well beyond system startup, and well beyond service management, and
citing s6 or launchd or whatever misses the war by focusing on the battle.
d