On Tue, Sep 29, 2015 at 10:40 AM, Laurent Bercot
<ska-skaware_at_skarnet.org> wrote:
>
> Ah, OK, I understand.
> I'd argue that you can convert more or less painlessly by making all your
> services oneshots that call the appropriate init.d/foo scripts and
> forgetting about supervision entirely. As soon as you try digging into
> stuff and actually taking advantage of the supervision tree, it becomes
> work that needs brain involvement, I'm afraid.
>
WIth the exception of udev everything that runs in single user mode
(scripts in rcS.d) are either oneshots in the classic sense or easily
rewritable as supervised services. I'm not worried about the stuff
I've rewritten changing definitions on me because all the movement
happens in either config files or in the sanitization or daemonization
areas of the init script (iow, all the stuff you stop worrying about
when supervising stuff). The various oneshot scripts in rcS.d I'm
calling as oneshots from s6-rc, so again, no worries on movement.
udev, being a freedesktop special child, has both oneshot (cleanup,
sanitization, prep) and longrun (daemonization) operations intermixed
in the same script which makes things suck. Hence my current stupid
hack of calling the init script, stopping the daemonized udev, and
then starting a properly supervised udev right after.
I'll probably end up starting a supervised udev and then calling a
hand-rolled oneshot prep script, but it's not ideal from a distro
cutover perspective. I'm ok doing that work, but folks who swing by
wanting to try out the s6-rc/s6-init hotness will either end up with a
non-supervised udev (non-ideal) or a hack of equal-or-worse uglyness
to the one I've got currently. Either way, testing in odd (or not so
odd as the case may be) circumstances is a good way to find out where
the shims are needed and what pain points folks with enthusiasm but no
experience are going to run into.
Cheers!
--
"If the doors of perception were cleansed every thing would appear to
man as it is, infinite. For man has closed himself up, till he sees
all things thru' narrow chinks of his cavern."
-- William Blake
Received on Tue Sep 29 2015 - 20:27:01 UTC