From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= Subject: Re: Services and log management/monitoring Date: Fri, 19 Apr 2019 14:09:34 +0200 Message-ID: <87imvaci2p.fsf@gnu.org> References: <67f09d8d-3ca6-90a0-6e72-c85ec9d1572f@s.rendaw.me> <87bm1472ha.fsf@gnu.org> <4428ea68-57fe-5459-0e26-529bc05d0b31@s.rendaw.me> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([209.51.188.92]:39402) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hHSKm-0005yw-Hx for help-guix@gnu.org; Fri, 19 Apr 2019 08:09:37 -0400 In-Reply-To: <4428ea68-57fe-5459-0e26-529bc05d0b31@s.rendaw.me> (rendaw's message of "Fri, 19 Apr 2019 00:11:49 +0900") List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-guix-bounces+gcggh-help-guix=m.gmane.org@gnu.org Sender: "Help-Guix" To: rendaw <7e9wc56emjakcm@s.rendaw.me> Cc: help-guix@gnu.org Hi, rendaw <7e9wc56emjakcm@s.rendaw.me> skribis: > I think fundamentally what I'd most like to know is when should I use a > Shepherd service vs a non-Shepherd service.=C2=A0 Maybe it's as simple as= : if > you don't have any specific requirements always define a Shepherd service. It=E2=80=99s hard to answer that question in the abstract. Do you have an example in mind that we could work through? > As a metaphor, maybe Shepherd services would be similar to the plain > units in systemd. Yes, I think so. > Beyond what a service actually is though I have a few more questions: > > * Both > https://www.gnu.org/software/guix/manual/en/html_node/Service-Composition= .html > and > https://www.gnu.org/software/guix/manual/en/html_node/Shepherd-Services.h= tml#Shepherd-Services > appear to show a dependency graph. The first page shows a service extension graph. The second page shows a graph of dependencies among Shepherd services. These are two different beasts. > =C2=A0 Are the dependency graphs Shepherd and non-Shepherd services > entirely separate?=C2=A0 Or maybe I'm completely misunderstanding > "extension" in this context.=C2=A0 Can an inet service depend on a non-in= et > service?=C2=A0 Can an inet service depend on a d-bus service? * Is there= a > way to hook into service events - that is, run some code when a > service starts or stops? An inetd service cannot =E2=80=9Cdepend=E2=80=9D on a non-inetd service; a = D-Bus service cannot depend on a non-D-Bus service. Both D-Bus and inetd have their own notion of what a service is, how to start it, etc., which is separate from what the Shepherd does. I reckon that calling everything a =E2=80=9Cservice=E2=80=9D does not help = understand all this=E2=80=A6 HTH, Ludo=E2=80=99.