Re: s6 readiness support

From: Laurent Bercot <ska-skaware_at_skarnet.org>
Date: Wed, 25 Feb 2015 23:13:47 +0100

On 25/02/2015 22:29, Patrick Mahoney wrote:
> The loopwhilex keeps the pump primed, so to speak, so /service/s can
> be stopped and started many times with readiness reporting working.
> Otherwise, I'd need to restart /service/s/log as well as /service/s.
>
> On the other hand, I have mostly idle backtick and head commands hanging
> around.

  How about
  pipeline -w
  {
     cd ..
    forbacktickx -d"\n" i { cat } s6-notifywhenup -f echo
  }
  ...
  ?

  If you don't mind using a shell, you can even have a single shell
lying around instead of both a forbacktickx and a cat process:
    /bin/sh -c "while read ; do s6-notifywhenup -f echo ; done"

  (But really, "s6-ftrig-notify event U" is less hackish than
"s6-notifywhenup echo".)

  And this need for a "cat" process makes me think forbacktickx is
badly designed. It should parse its own stdin instead of spawning
a command; forbacktickx functionality can be achieved by combining
the parse-stdin program with pipeline.

-- 
  Laurent
Received on Wed Feb 25 2015 - 22:13:47 UTC

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