Re: [announce] s6-rc: a s6-based service manager for Unix systems

From: Colin Booth <cathexis_at_gmail.com>
Date: Tue, 29 Sep 2015 10:06:12 -0700

On Sep 29, 2015 9:06 AM, "Laurent Bercot" <ska-skaware_at_skarnet.org> wrote:
>
> On 29/09/2015 17:50, Colin Booth wrote:
>>
>> Still an open question on correct ordering. I want to do this:
>> 1) udev longrun
>> 2) udev support oneshot
>>
>> But I also don't want to maintain a patch set for init.d/udev to remove
the
>> start call to udev itself since udev is perfectly happy to have multiples
>> running.
>
>
> I'm afraid I'm not following. What is init.d/udev doing at this point
> that you cannot do as a longrun+oneshot? What would need to be patched?
>
init.d/udev creates static nodes, starts udev, cleans up after the
initramfs udev, and finally fully populates /dev. The problem is that if I
run udev as a longrun and then call the packaged script, I'll end up with
two copies of udev running - one supervised, one not. That can be fixed by:
patching the init script to not call udev, running the init script first
then telling the unsupervised udev to shut down before starting the
supervised one, or copying only the useful parts of the init script into
the oneshot definition and ignoring the udev init script entirely.

I'd go with the third - hand-rolling a udev oneshot definition - if I
wasn't trying to stick as close as possible to stock Debian and the udev
init script has been a (slowly) moving target, at least in the unstable
branch.

Again, the goal (implied, but unstated) here isn't "test to see if s6-rc
works for end-to-end system management" (it definitely does), the goal is
"see how much work/pain in the ass it is to convert a typical end-user
system* to s6-rc." Hence all the hand-wringing about trying to stick close
to a stock Debian and not wanting to modify init scripts. And yes, one
could argue that by doing an init swap it already is pretty different from
stock, but that's beside the point.

Cheers!

*"typical end user system" being: low-mid power, laptop-like (wireless,
power managed, sleep capabilities), running an up-to-date mainstream distro.
Received on Tue Sep 29 2015 - 17:06:12 UTC