Re: First thoughts on s6

From: Laurent Bercot <ska-supervision_at_skarnet.org>
Date: Wed, 17 Jun 2015 03:04:47 +0200

On 17/06/2015 02:44, Steve Litt wrote:
> Plop Linux has one of those /dev/random generators that just stops
> after a few characters. This caused the ./configure on skalibs to lock
> up while checking for /dev/random (thank you very much for the clear
> messages). In fact, /dev/random on this VM locks up dd too. I
> strongarmed the problem by removing /dev/random and making a hard link
> called /dev/random to /dev/urandom.

  http://skarnet.org/software/skalibs/flags.html#forcedevr

  The --enable-force-devr option is also mentioned in ./configure --help.
I expect people to at least read ./configure --help ! :P


> My tty5 takes 1 second from Ctrl+D til the time the next login prompt
> is printed. Is this a feature, or a bug?

  Feature. There's always a 1-second delay before a service respawns.
Other people have also expressed dislike, but I really want to make
sure services never respawn too fast. I have an idea to get the best
of both worlds, but haven't gotten around to implementing it yet.

  
> The following two commands worked *very* differently:
>
> * cat /service/tty5/log/main/current | tai64nlocal
>
> * cat /service/tty5/log/main/current | tai64n

  Um, yes? s6-tai64n prepends every line with a timestamp,
whereas s6-tai64nlocal converts TAI64N timestamps into local time
ISO 8601 timestamps.
  Your logs have already been timestamped by s6-log. If you
filter them through s6-tai64nlocal, the existing timestamps will be
converted, and that is what you are witnessing.
  If you filter your logs through s6-tai64n, though, what will
happen is that a new, additional timestamp will be prepended to
every line. This is also what you are witnessing, and probably not
what you want, but then why are you doing this? XD


> I think the following additions would make the s6 website a lot easier
> to use, and a lot easier for somebody to begin using s6:
>
> * FAQ

  Can you give me an example of questions you had that were not
covered by the overview ?


> * A page with simple files, including run and log/run for a tty.

  Yeah. Remember that s6 aims to be system-agnostic, though, and
it's *very* easy to fall into linuxisms as soon as you start
doing that kind of thing. I'm not sure your getty run script works
under BSD, for instance. :)

-- 
  Laurent
Received on Wed Jun 17 2015 - 01:04:47 UTC

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