[gentoo-dev] OpenRC and SystemD Config File Parity

[gentoo-dev] OpenRC and SystemD Config File Parity

[Jason A. Donenfeld]

Hey everyone,

This isn't a topic meant for bike shedding, but just kind of loose
exploratory inquiry. I saw a bug report about adding systemd's
tmpfiles.d config format support to OpenRC (accomplished) and then
some discussion about adding an ebuild utility function (dotmpfiles_d)
or digging up something from systemd.eclass for this. This whole
discussion got me thinking --

To what degree is there parity of configuration formats between OpenRC
and SystemD? Obviously there will never be any sort of parity ever for
Unit files, but what about for the general parameters of the system?
machine-id, locale, timezone, hostname, et cetera.

I suppose when I refer to OpenRC, I'm really talking about Baselayout.

I guess more specifically what I'm wondering is:

- What is the current state of differences between config file formats
and locations used for OpenRC/Baselayout and SystemD?
- Is parity desirable? Are some people working on this?
- Are there advantages / disadvantages? Which files, for what, and why?


Anyway, if folks have opinions or thoughts, I'd love to hear them. But
this is just loose inquiry, not a pressing question for a project in
motion, so don't feel compelled to exsanguinate your soul here.

Jason

Re: [gentoo-dev] OpenRC and SystemD Config File Parity

[heroxbd]

"Jason A. Donenfeld" <Jason@zx2c4.com> writes:

> To what degree is there parity of configuration formats between OpenRC
> and SystemD? Obviously there will never be any sort of parity ever for
> Unit files, but what about for the general parameters of the system?
> machine-id, locale, timezone, hostname, et cetera.

In OpenRC they are mostly in /etc/conf.d. How about systemd?

> I suppose when I refer to OpenRC, I'm really talking about Baselayout.
>
> I guess more specifically what I'm wondering is:
>
> - What is the current state of differences between config file formats
> and locations used for OpenRC/Baselayout and SystemD?

config file formats differs a lot, for OpenRC it's shell script, while
for SystemD Microsoft ini/XDG Desktop Entry Specification.

> - Is parity desirable? Are some people working on this?

Thought of that before, but haven't gain much motivation yet.

> - Are there advantages / disadvantages? Which files, for what, and
> why?

I'm not sure.

> Anyway, if folks have opinions or thoughts, I'd love to hear them. But
> this is just loose inquiry, not a pressing question for a project in
> motion, so don't feel compelled to exsanguinate your soul here.

Oh I'm scared ;)

Re: [gentoo-dev] OpenRC and SystemD Config File Parity

[Jason A. Donenfeld]

On Fri, Aug 17, 2012 at 7:33 AM,  <heroxbd@gentoo.org> wrote:
> config file formats differs a lot, for OpenRC it's shell script, while
> for SystemD Microsoft ini/XDG Desktop Entry Specification.

Sorry, just to clarify and reiterate what I said before -- I am
excluding Unit files from this discussion, for obvious reasons. Unit
files are the ini files you commented there. My inquiries are directed
toward the other more global system configuration files that systemd
and openrc use. Again, the discussion is not about Unit files, ini, or
shell scripts vs systemd units; this is considered off-topic.

Re: [gentoo-dev] OpenRC and SystemD Config File Parity

[Michał Górny]

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On Fri, 17 Aug 2012 03:23:52 +0200
"Jason A. Donenfeld" <Jason@zx2c4.com> wrote:

> This isn't a topic meant for bike shedding, but just kind of loose
> exploratory inquiry. I saw a bug report about adding systemd's
> tmpfiles.d config format support to OpenRC (accomplished) and then
> some discussion about adding an ebuild utility function (dotmpfiles_d)
> or digging up something from systemd.eclass for this. This whole
> discussion got me thinking --
> 
> To what degree is there parity of configuration formats between OpenRC
> and SystemD? Obviously there will never be any sort of parity ever for
> Unit files, but what about for the general parameters of the system?
> machine-id, locale, timezone, hostname, et cetera.

> - What is the current state of differences between config file formats
> and locations used for OpenRC/Baselayout and SystemD?

Some of the configs are systemd-specific and were adjusted in Gentoo.
For example, machine-id was moved from /var/lib/dbus to /etc.

With a few other configs, systemd supports both OpenRC and its own
format. When used with --with-distro=, it finds and reads Gentoo
configs; you can also replace them with native systemd files.

And finally, there are configs which are both used by systemd
and OpenRC, like binfmt.d, tmpfiles.d, modules-load.d. The former two
we adopted to avoid reinventing the wheel, not sure about the last one.

It's all on the wiki: http://wiki.gentoo.org/wiki/Systemd#Configuration

> - Is parity desirable? Are some people working on this?

Some people are thinking about this. Unit files are especially
desirable since that's what upstreams are often shipping. There's no
point in keeping init.d files in sync when we can use upstream-managed
units.

> - Are there advantages / disadvantages? Which files, for what, and
> why?

The same as usual.

Adv:
- users don't have to remember a few locations when working with
  different distros or learn when switching,
- tools can be designed for a single location,
- upstream can provide some files for us.

Disadv:
- a bit more work on our side,
- a few people will complain about systemd dominating their systems,
- a few people will end up with broken systems through removing
  everything looking suspiciously systemd-matic.

-- 
Best regards,
Michał Górny

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