Sam Hartman (hartmans) wrote,
Sam Hartman
hartmans

Voting Guide for Debian Init Systems GR

There are a lot of options on the ballot for the Init Systems GR.
There have been hundreds of messages on debian-vote, and more scattered
across debian-devel, debian-project, and bugs. Reading all that is no
easy task. so I would like to summarize my understanding of the options
and what they would mean. I've tried to remove as much bias as I can,
but this is still Sam's personal opinion.



I'm focused entirely on the effects of the proposals. Several options
(D, F, and G) spend significant time outlining principles. That is
something I'm ignoring here in this post, although I acknowledge it is
really important to some.



Areas of Agreement



One of the big surprises for me in this discussion is things that are
true of all the ballot options so far. We are agreed that programs
designed to use systemd features that only work with systemd are welcome
in Debian. That's true even if there is no way for these programs to
work without systemd. Under Proposal D, this is a bug, but not a
release-critical bug.



Init Diversity Options


Several options focus on encouraging or requiring packages to support
init systems others than systemd when that is possible. These include
Proposal
E
, Proposal F,
and Proposal
A
. Under proposal E, it is a release critical bug if a program does
not work when something other than systemd is pid 1 unless that program
is designed explicitly to work with systemd and no support for running
without systemd is available. Lack of an init script alone is not
sufficient to count as designed to work exclusively with systemd.



So, under this proposal, a maintainer must integrate support for running
without systemd if it is available. They are responsible for going out
and finding this support. If the support is as simple as writing an
init script, the maintainer has an RC bug until they write the init
script. If the support is more complex, the maintainer is not
responsible for writing it. Proposal A is the same as Proposal E,
except that the bug is not release-critical. I'll go into Proposal A in
more detail after discussing Proposal D.



Proposal D is similar to Proposal E. My interpretation is that Proposal D places
somewhat less of a burden on maintainers to go out and find existing
non-systemd support. My interpretation is that the bug becomes RC when
someone contributes that support. (Or if the support is present in the
upstream but turned off in the package). Proposal D requires that
non-systemd support not have a substantial effect on systemd
installations. So where as Proposal E uses the designed exclusively for
systemd criteria, Proposal D uses the no substantial effect on systemd
systems criteria to determine whether working only with systemd is
acceptable. The discussions seemed to imply that if Gnome uses systemd
features in excess of what technologies like elogind can handle, it is
likely to meet both criteria.



Proposal D goes into a lot more detail than Proposal E. Proposal E
would likely be a long-term block on using systemd facilities like
sysusers. Proposal D specifically proposes a mechanism whereby such
facilities can be documented in policy. This mechanism is only
available if it is likely that developers of non-systemd (including
non-Linux) systems will implement the facility. After a six-to-twelve
month transition time, the facility can be used even on non-systemd
systems. So, sufficiently low effort in the non-systemd community that
it is unreasonable to expect a facility could be implemented could still
permanently block adoption of such facilities. Proposal D is definitely
about a long-term commitment to non-systemd systems even if the effort
in the non-systemd community is not as high as we'd like to adopt new
features elsewhere.



Proposal D also includes a number of guidelines for proper behavior
around these emotionally charged issues.



The only difference between Proposal E and Proposal A is the severity of
the bug when non-systemd support is not in a package. In Proposal A,
this bug is important: potentially sufficient for a stable update, but
not release critical. As a practical matter, Proposal A allows the
non-systemd community to contribute (and NMU) patches for non-systemd
support. However, it does not place an obligation on maintainers to
write this support themselves. Proposal A would permit systemd
facilities like sysusers to be used, although doing so might be a bug.
In the specific case of sysusers, someone could justify NMUing a patch
to use adduser in a maintainer script. Unlike Proposal D, Proposal A
places the burden of keeping up with systemd facilities fully on the
non-systemd community. Proposal A does not have Proposal D's
requirement that it be reasonable to expect that the non-systemd
community can implement the facility.



Systemd Options


There are two systemd options: Proposal F
and Proposal
B
. Proposal F replaces a previous Proposal C. As far as I can tell
Proposal F and C do the same thing, but Proposal F has some text
describing principles. As I said in the introduction, I'm not
discussing that here.



Under Proposal F, systemd is the only officially supported option.
Other init systems may be explored at wishlist priority. Systemd
facilities such as sysusers are encouraged, and we will use our usual
mechanisms to plan transitions from Debian facilities where appropriate.



Proposal B does not explicitly say that alternate init system work can
only be wishlist. Under Proposal B, I think it would be reasonable to
file some bugs at normal severity, but it would also be reasonable for a
maintainer to downgrade them. I don't consider that a significant
difference.



The big difference is that Proposal B commits us as a project to
reviewing integrations of technologies that are alternatives to
systemd facilities. The current example is elogind. But things like
a non-systemd implementation of sysusers, tmpfiles.d, etc, would also
qualify. The rationale is that sometimes alternatives like that touch
on core infrastructure, and even if other maintainers are doing the
work, gatekeeper review is needed. Under Proposal B, the alternate technologies would be available, but whether to use them in a specific package would be up to the maintainer. I've discussed in another, more opinionated blog post why this might be a good idea.



Proposal G


As best I can tell Proposal G is just a set of principles. so, in the context of the analysis I have set out to perform here, I think there is nothing to say.

Tags: debian
Subscribe

Recent Posts from This Journal

  • The Case for Proposal B

    This is my personal opinion, not that of the project leader. Tomorrow, I'll write an essay trying to discuss the various options in with as little…

  • Free as in Sausage Making: Inside the Debian Project

    Recently, we’ve been having some discussion around the use of non-free software and services in doing our Debian work. In judging consensus…

  • AH/DAM/DPL Meet Up

    All the members of the Antiharassment team met with the Debian Account Managers and the DPL in that other Cambridge— the one with proper behaviour,…

  • Post a new comment

    Error

    default userpic

    Your reply will be screened

    Your IP address will be recorded 

    When you submit the form an invisible reCAPTCHA check will be performed.
    You must follow the Privacy Policy and Google Terms of use.
  • 0 comments