:: Re: [DNG] Runit service depend anot…
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Autor: viverna
Fecha:  
A: dng
Asunto: Re: [DNG] Runit service depend another script not daemon
il devuanizzato Steve Litt <slitt@???> il 04-07-19 22:23:51 ha scritto:
>Hi viverna,
>
>I have a very different viewpoint than most people, so the following is
>*my opinion* and is not in the mainstream.
>
>I think that, for both s6 and runit, run scripts (and any finish
>scripts or environment files) should come from a small committee of
>runit/s6 experts, NOT from the overworked "upstreams" who created the
>software, nor the overworked distro-based maintainers who adapt the
>software to the distro. During the Debian-User systemd war, one of the
>greatest sources of resistance to multi-initism was "upstreams" and
>maintainers who bitched about now having to take care of an extra set
>of init scripts.
>
>If each "upstream" simply documents:
>
>1) How to run the software, in the foreground, without excessive
> logging.
>2) The preferred user and group to run the software.
>3) What daemons should already be running before the software.
>4) Any special state circumstances necessary to start the software. For
> instance:
> * Network up
> * Such and such file with so and so permissions
> * Etc.
>5) Any cleanup that must be done after the software finishes or crashes.
>6) Any environment vars the software is responsive to.
>7) The software's response to any signals.
>8) Any special logging the software does all by itself.
>9) Does it require a "twin" daemon, like smbd and nmbd, and if so,
> which should start first?
>
>Possessing the preceding info, it's easy to make an s6 or runit run
>script, finish script, and if necessary environment file. In most cases
>only the first 4 are really necessary. If an "upstream" refuses to
>answer the questions, the info can probably be gleaned from the
>software's systemd unit file.
>
>This list of questions could be sent to each "upstream", and the
>answers will almost 1 for 1 correspond to the run script.
>
>The runit package could install tree /etc/runit/scriptdirs and the
>directory /etc/sv, and a daemon's (call it mydaemon) install could
>include something like the following:
>
>if -d /etc/runit/scriptdirs; then
> ln -s /etc/runit/scriptdirs/mydaemon /etc/sv/mydaemon
>fi
>
>Uninstalling the mydaemon package would remove symlink /etc/sv/mydaemon.
>
>My method runs counter to the way it's always been done, and I always
>get a lot of pushback when suggesting it, but my way would probably
>limit resistance from "upstreams" and maintainers, and would not
>require those people to become runit and/or s6 experts. Meanwhile, it
>would be trivial for a couple runit and s6 experts to write the actual
>startup files, based on the "upstream"s answer to a few simple
>questions.
>
>SteveT
>
>Steve Litt
>July 2019 featured book: Troubleshooting Techniques
>     of the Successful Technologist
>http://www.troubleshooters.com/techniques
>_______________________________________________
>Dng mailing list
>Dng@???
>https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng

Sounds like a good solution to me, however the main problem remains; all
packaged daemon must implement (at install phase) the simple script you
specified above.
How to do? Devuan, if I'm not wrong, get packages from Debian for all
packages with no systemd hard dependency.
Devuan is a great distro and has excellent developers but limited
manpower.
I think that fork all daemon is not praticable. Instead it's possible
inject in all daemon's install a piece of posix shell?
Workaround script on event "DPkg::Post-Invoke" as I said in the previous
email? Else is better another strategy?
These are questions that I ask myself but it's important for the future
of Devuan and init systems diversity.
The choice of Debian is to follow freedesktop "fancy" guy. It is not
difficult to think of the day when Debian will remove completely
sysvinit script in all packages.

--
viverna