From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org
X-Spam-Level: 
X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI
	autolearn=ham autolearn_force=no version=3.4.4
Received: (qmail 23253 invoked from network); 2 Aug 2021 21:40:41 -0000
Received: from alyss.skarnet.org (95.142.172.232)
  by inbox.vuxu.org with ESMTPUTF8; 2 Aug 2021 21:40:41 -0000
Received: (qmail 19747 invoked by uid 89); 2 Aug 2021 21:41:05 -0000
Mailing-List: contact supervision-help@list.skarnet.org; run by ezmlm
Sender: <supervision@list.skarnet.org>
Precedence: bulk
List-Post: <mailto:supervision@list.skarnet.org>
List-Help: <mailto:supervision-help@list.skarnet.org>
List-Unsubscribe: <mailto:supervision-unsubscribe@list.skarnet.org>
List-Subscribe: <mailto:supervision-subscribe@list.skarnet.org>
List-Id: <supervision.list.skarnet.org>
Received: (qmail 19740 invoked from network); 2 Aug 2021 21:41:05 -0000
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
Message-Id: <em5ad7e7e2-e028-4aa6-9999-f631a8f6f60b@elzian>
In-Reply-To: <20210802164201.331cafaf@mydesk.domain.cxm>
References: <CAHJ2E==Uq7RFNCH-zLEU5Vn74XvEZHb11M5MNDgfaDVXvp1K_Q@mail.gmail.com>
 <em5397e5ea-1525-404b-9490-b39ef0cea0a6@elzian>
 <20210802140732.316b9f4d@mydesk.domain.cxm>
 <em53404023-b5de-45d0-aad2-18dd54e8a436@elzian>
 <20210802164201.331cafaf@mydesk.domain.cxm>
Reply-To: "Laurent Bercot" <ska-supervision@skarnet.org>
User-Agent: eM_Client/8.2.1473.0
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: quoted-printable
X-VR-SPAMSTATE: OK
X-VR-SPAMSCORE: -100
X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvtddriedvgdduheduucetufdoteggodftvfcurfhrohhfihhlvgemucfpfgfogfftkfevteeunffgpdfqfgfvnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvffufffkjghfrhgfgggtgfesthhqredttderjeenucfhrhhomhepfdfnrghurhgvnhhtuceuvghrtghothdfuceoshhkrgdqshhuphgvrhhvihhsihhonhesshhkrghrnhgvthdrohhrgheqnecuggftrfgrthhtvghrnhepvdfgveffueelgedvkedtffetgedvieeifeektefgueehffehleehjefhveeuieejnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpohhuth

>Do you think this is any better?
>
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
>#!/bin/sh
>test_for_myrequirement || exit 1
>exec mydaemon -myarg1 -myarg2
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

  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