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Author: Steve Litt
Date:  
To: dng
Old-Topics: Re: [DNG] Lennart now working for Microsoft
Subject: [DNG] s6: was Lennart now working for Microsoft
wirelessduck--- via Dng said on Sun, 10 Jul 2022 00:06:13 +1000


>Here’s to hoping that Laurent Bercot’s (skarnet) new process
>supervision software arrives and is ready to go before any potential
>systemd implosion occurs.


You can use s6 as a pure process supervisor today, by using sysvinit as
PID1 only and running all processes off s6. You can do the same thing
with runit.

>Does anyone know where we can keep track of progress on that project?


Yes. The supervision mailing list:

    supervision: Discussion about system services, daemon
    supervision, init, runlevel management, and tools such as s6
    and runit. To subscribe, send an empty message to
    supervision-subscribe@???.


>His website hasn’t seen any updates since the funding announcement a
>long time ago.
>
>https://skarnet.com/projects/service-manager.html


The preceding web page is a project manifesto, not a report on
progress. My understanding is that for the reasonable things we
Devuaners do every day, the s6-linux-init and s6-rc programs are
already capable of creating an s6 only init system with an s6 PID1. My
impression is what Laurent is working on now is the (unwise)
incorporation of better written versions of all systemd features.

Just as a humorous aside, years ago I created something called
the LittKit API that would make any Daemontools, Daemontools-encore,
runit or s6 supervisor init with a specific order and intermix one-shot
and long-run processes. The API implementation must be changed slightly
for each one of those supervisors, but the API interface remains the
same. You can see the LittKit proof of concept at
http://troubleshooters.com/projects/littkit/ and
http://troubleshooters.com/linux/diy/suckless_init_on_plop.htm .

Speaking just for myself in my 7 years of runit, indeterminate startup
is not a problem if you put dependency tests into your run scripts.
Common sense says that indeterminate startup would be a bad thing, but
I've not run across disadvantages. If I ever wanted determinate process
startup, I could either use s6 plus s6-rc, or I could apply LittKit to
runit.

SteveT

Steve Litt
March 2022 featured book: Making Mental Models: Advanced Edition
http://www.troubleshooters.com/mmm