supervision - discussion about system services, daemon supervision, init, runlevel management, and tools such as s6 and runit
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From: "Laurent Bercot" <ska-supervision@skarnet.org>
To: "Steve Litt" <slitt@troubleshooters.com>, supervision@list.skarnet.org
Subject: Re: S6 Queries
Date: Mon, 02 Aug 2021 21:40:39 +0000	[thread overview]
Message-ID: <em5ad7e7e2-e028-4aa6-9999-f631a8f6f60b@elzian> (raw)
In-Reply-To: <20210802164201.331cafaf@mydesk.domain.cxm>

>Do you think this is any better?
>
>=============================
>#!/bin/sh
>test_for_myrequirement || exit 1
>exec mydaemon -myarg1 -myarg2
>=============================

  This does not accomplish the same thing at all: it does not ensure
that myrequirement is at least attempted before mydaemon runs. Instead,
it conditions the readiness of mydaemon to that of myrequirement. So,
it is "better" in the sense that it does not control another service
from a run script, but it is even further from what the OP wants.

  Any reference to another service in a  run script is going to be quirky
at best. Managing all kinds of dependencies between services is really
best done *outside* of run scripts, which is why s6-rc exists. It does
not currently have all the expressive power of systemd for dependencies,
but in the future, it will.

--
  Laurent


  reply	other threads:[~2021-08-02 21:40 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-02  4:54 Arjun D R
2021-08-02  8:27 ` Laurent Bercot
2021-08-02 18:07   ` Steve Litt
2021-08-02 19:39     ` Laurent Bercot
2021-08-02 20:42       ` Steve Litt
2021-08-02 21:40         ` Laurent Bercot [this message]
2021-08-11 11:05   ` Arjun D R
2021-08-11 14:21     ` Laurent Bercot

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