From: "Brett Neumeier via supervision" <supervision@list.skarnet.org>
To: Paul Sopka <psopka@sopka.ch>
Cc: "supervision@list.skarnet.org" <supervision@list.skarnet.org>
Subject: Re: Have an external script wait for a oneshot service
Date: Wed, 4 Dec 2024 14:18:21 -0600 [thread overview]
Message-ID: <20241204141821.ee2a00c996c948f2feb42dec@freesa.org> (raw)
In-Reply-To: <2571a89b-ac74-4d9e-b8c6-ff0fe05cebb7@sopka.ch>
On Wed, 4 Dec 2024 21:05:45 +0100
Paul Sopka <psopka@sopka.ch> wrote:
> > You could use `s6-rc -a list`, perhaps? It lists all services that are in the active state.
> >[...]
> > Does that give you what you want?
> Unfortunately not, since I specifically need to *wait*
> and waiting based on "state-info" would require polling,
> which I would rather avoid.
Ah, I see: from your external script, you do not want to know *whether* a oneshot service has completed; you want to block *unless or until* it has completed?
In that case, I would use `s6-ftrig-notify` in the oneshot service, and both `s6-rc -a list` and `s6-ftrig-wait` in the external script:
in the oneshot, as the last action taken before quitting, use `s6-ftrig-notify` to send an event to a fifodir;
in the external script, `s6-rc -a list | grep -q $(oneshot_service_name)` to proceed if the oneshot is already up, and then if it is not up, `s6-ftrig-wait` to block until it is.
Or, as you say, you can use fifodirs directly without the convenience programs that interact with them already.
There might be a race condition there, but that's something you can surely work around if it's a concern.
--
Brett Neumeier <random@freesa.org>
next prev parent reply other threads:[~2024-12-04 20:18 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-04 15:28 Paul Sopka
2024-12-04 15:38 ` Charles Cazabon via supervision
2024-12-04 17:12 ` Paul Sopka
2024-12-04 21:47 ` Hoël Bézier
2024-12-04 20:00 ` Brett Neumeier via supervision
2024-12-04 20:05 ` Paul Sopka
2024-12-04 20:18 ` Brett Neumeier via supervision [this message]
2024-12-04 20:59 ` Paul Sopka
2024-12-04 21:58 ` Re[2]: " Laurent Bercot
2024-12-05 5:59 ` Tanuj Bagaria
2024-12-05 6:54 ` Paul Sopka
2024-12-05 8:05 ` Re[2]: " Laurent Bercot
2024-12-05 13:52 ` Paul Sopka
2024-12-05 19:44 ` Re[2]: " Laurent Bercot
2024-12-05 21:10 ` Paul Sopka
2024-12-05 21:42 ` Brett Neumeier via supervision
2024-12-06 5:32 ` Paul Sopka
2024-12-05 23:03 ` Re[2]: " Laurent Bercot
2024-12-06 12:41 ` Paul Sopka
2024-12-06 15:43 ` Re[2]: " Laurent Bercot
2024-12-06 16:11 ` Hoël Bézier
2024-12-06 17:14 ` Paul Sopka
2024-12-07 23:46 ` Jan Braun
2024-12-05 21:24 ` Jan Braun
2024-12-05 23:15 ` Re[2]: " Laurent Bercot
2024-12-04 20:09 ` Tanuj Bagaria
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