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From: Jeff <sysinit@yandex.com>
To: super <supervision@list.skarnet.org>
Subject: killall test run
Date: Sun, 19 May 2019 14:57:14 +0200	[thread overview]
Message-ID: <9538981558270634@myt3-c573aa6fc782.qloud-c.yandex.net> (raw)
In-Reply-To: <d1a7fe4d-19cb-db6d-b322-8e9e00af06a4@obarun.org>

19.05.2019, 13:24, "fungal-net" <fungalnet@obarun.org>:
> I am glad some of you can tell more than I can about this, and since you
> did I tried my weirdest of setups. This is Adélie adelielinux.org
> installation on HD. Although it is confusing to me how they set this up
> still, after months of following its development (beta3), there is
> sysvinit on the first steps of booting then OpenRC takes over, and then
> s6-supervisor handles everything running. It is like a fruit punch in
> my eyes. For those that don't know this is built on musl.

they use SysV init + OpenRC (with some scripts from Alpine)
OpenRC is known to work with s6-svscan (this is done via the
/libexec/rc/sh/s6.sh shell script). although it is better to start
s6-svscan from /etc/inittab (directly or - as i prefer - via a starter
shell/execline script that ensures at least the scandir exists)
since SysV init can respawn processes anyway (supervised
supervisor ;-).

by default OpenRC (better: s6.sh) uses /run/openrc/s6-scan as the
service scandir and /var/svc.d as service template dir, this can
be changed easily of course since only shell scripts are involved here.
when starting an s6 service it copies the service template dir into
the scandir /run/openrc/s6-scan. for this to work properly an already
running instance of s6-svscan (that runs on said scandir) is required.
OpenRC achieves this by adding "s6-svscan" to the "need" call in
the depend function of the corresponding service script.

when starting s6-svscan from inittab OpenRC does not have to
start it and there is no need to start the s6-svscan nor to add it to
other services' dependencies. although i do not know the order
in which sysvinit processes the inittab entries for a given (SysV)
"runlevel". do "wait" entries precede "respawn" entries, followed
by the "once" entries ? dunno, this needs a bit of hackery to make
it work but this ordering/dependency problem is definitely solvable.

> # kill -9 -1 on tty1 brought me back to tty1 login screen with 5 more
> ttys active. So everything is respawned almost instantly to a system
> just like it had just booted. Doing the same from terminal on X had the
> same exact outcome.

as expected. :D

> Both s6/s6-rc and 66 pkgs are available through void's repositories but
> s6-rc has been modified and I haven't been able to get it to work.

you can find out easily about your init via
$ ps -Fjlp 1
also have a look in the /proc/1 dir when procfs is mounted on /proc,
the target of the exe symlink is of interest here.

to see how all this is organised check with
$ ps -FHjle fww
BEFORE kill -1 -9 and again after sending the kill blast.

> Void uses arch-like /bin /sbin --> /usr/bin,

yes, i noticed this too. this is not "arch" like but was invented by fedora/
red hat instead. being the fedora testbed the lame arch distro had
to follow suit immediately as is typical for them.

> Adélie has more traditional 4 separate directories.

this is what one would expect.




  reply	other threads:[~2019-05-19 12:57 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-29 19:19 interesting claims Jeff
2019-04-30  2:49 ` Guillermo
2019-04-30  8:22 ` Laurent Bercot
2019-05-03  0:53   ` what init systems do you use ? Jeff
2019-05-11 18:45     ` Guillermo
2019-05-13 19:13     ` multiplexd
2019-05-13 20:36       ` Laurent Bercot
2019-05-13 21:09       ` Steve Litt
2019-05-14  2:34         ` Guillermo
2019-05-13 21:16       ` Joshua Ismael Haase Hernández
2019-05-14  5:50     ` Colin Booth
2019-05-14  7:15       ` eric vidal
2019-04-30  8:47 ` interesting claims Jonathan de Boyne Pollard
2019-05-01  7:26 ` Steve Litt
2019-05-01  7:33 ` Steve Litt
2019-05-01 18:13   ` Laurent Bercot
2019-05-15 17:22     ` Steve Litt
2019-05-15 23:22       ` Oliver Schad
2019-05-16  1:07         ` Steve Litt
2019-05-16  5:36           ` fungal-net
2019-05-16  8:32             ` Laurent Bercot
2019-05-16 17:10               ` Jeff
2019-05-17  0:23               ` Dewayne Geraghty
2019-05-17 11:21               ` fungal-net
2019-05-17 22:57                 ` Guillermo
2019-05-18  0:52                   ` Jeff
2019-05-18 16:26                     ` fungal-net
2019-05-18 20:04                       ` Guillermo
2019-05-19 11:24                         ` fungal-net
2019-05-19 12:57                           ` Jeff [this message]
2019-05-19 17:29                             ` killall test run Colin Booth
2019-05-19 20:39                             ` Guillermo
2019-05-19 23:06                               ` Laurent Bercot
2019-05-19 20:35                           ` interesting claims Guillermo
2019-05-03  1:37   ` how to handle system shutdown ? Jeff
2019-05-03 19:25     ` Laurent Bercot
2019-05-05  0:52       ` is it required to call kill() from process #1 ? Jeff

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