RFC: Modularity Simplified
by Igor Gnatenko
Hello fellows,
After last publication on LWN about Fedora Modularity mess, I think it
is time to describe the idea I was proposing internally with few other
folks (Adam Samalik, Brian Exelbierd) back in the RH times.
Before I actually go deep, I'll try to answer main questions to myself
(so that you can understand why I am proposing this particular thing).
1. Do we want to package multiple streams only for "leaf" software or
any kind of it?
I believe that we need both, and we do support both. However, it might
not look as nice as it could:
* Need to create multiple repos for different "streams"
* Need to maintain epel7/epel8/f30/f31/master branches
* Package names have to be "mangled" (e.g. mozjs38, mozjs60) and it is
manual work
* However, those are supposed to be (according to the guidelines)
parallel-installable (and not be conflicting in any way)
Doing git merge / git cherry-pick and maintaining many git remotes
requires some advanced git knowledge and a time. And we can't actually
have multiple versions of a package with same name (without "mangled"
names) in a repo due to the way how our buildsystem works (and not
only buildsystem, with some caveats).
We do have some kind of a solution for multiple releases building from
one branch (package.cfg), however this work has been never finished,
thus there are many problems with this approach.
2. Do we want to support buildtime-only packages?
I would rather generalize this category as "less-supported packages".
I maintain 800+ Rust packages and very often I need to update them to
an incompatible version. In Rawhide I just do it, update all dependent
packages to use new version, and if I can't do that for some reason,
create "compat" package. Obviously, all patches are sent to the
upstream.
Upstreams are removing features, I need to deal with Obsoletes but I
simply can't continuously add new Obsoletes into the
fedora-obsolete-packages. And what for if they are used only during
build of other, more important, packages? Why do I have to spend time
with upgradepaths? I definitely want some mechanism which will tell to
user that "THIS PACKAGE IS NOT FULLY SUPPORTED."
Obviously, for packages which are used in runtime need a proper
support as we do today for all packages to share work (that's the
place where I agree with Kevin Kofler.)
3. Can we have different lifecycles for the software in Fedora?
Right now we have to keep all versions of software which was there at
GA point. And from the updates repo. We never remove packages
entirely. That said, if package was there at GA time, it will have to
be "supported" until the end of that Fedora release.
I don't think we can (should?) do much in this regard. If we make
packages to build from "stream" branch, we can put an information to
that branch that this package should be built for all distributions
(Fedora, EPEL) until this date. Or even store this info somewhere else
like PDC (yes, I know we want to kill it). fedpkg build will take this
into account and submit proper builds. And we can design some API in
infra which would tell until when some particular stream of a package
is supported. Much like it is done with Fedora releases & GNOME
Software.
4. Do we want to have some kind of "stream expansion" where software
builds against all Pythons, Perls and whatnot?
I think this should be conscious choice of a distribution, and in
specific cases, maintainer. Using some examples from previous threads,
why does bugzilla have to be built against 2 different versions of
perl and users could choose? I think maintainer should choose one
version of perl and let bugzilla use it. Being able to build
combinations of software is definitely nice, but I don't think this
should be standard practice. openSUSE does that with ruby and python
(they build all modules automatically for all versions) and I like
this. But having all packages built against all is just combinatoric
explosion. Given how many updates have feedback in Bodhi, I'm pretty
sure 99% of combination won't be tested (or even installed?) ever.
5. Are we still trying to be a Linux distribution or we are just
letting people to do whatever they want in our infrastructure?
This question bothers me from time to time and I don't have answer.
For example, Modularity is very flexible and I very often find people
saying that you can expand this and that, but in Fedora we limit its
usefulness. Do we actually need to develop something like this
(knowing in advance that probably nobody outside of Fedora/RHEL will
be using this software / technology)? Are we trying to create
technologies which would be very extensible and used in other
distributions instead of solving some specific problems? If former,
why don't we talk to others about things in advance and not getting
other people to work on these cool things?
===
How I would imagine having multiple streams:
* rpms/nodejs has multiple branches - 10, 11, 12
* in all of them, nodejs.spec exists as-is without "mangled" name
(just with different versions and such)
* each has package.cfg or some alternative which specifies what is the
EOL and/or for which releases to build
* when builds are submitted, Koji automatically adds suffix to a main
package and subpackages containing branch name
* during the rpmbuild, extra provides are added (for the unversioned
names and indication of a stream) and conflicts (possibly depending on
some macro which user can disable) automatically
Notes:
* If software needs to specify that it wants 9 ≤ nodejs ≤ 11 it can
describe this in standard way (Requires: (nodejs >= 9 with nodejs <=
11)) and one will be picked up automatically
* If user wants to switch from 9 to 10, he can run `dnf swap nodejs9 nodejs10`
* If that requires some conflicting dependency to be switched, it will
be switched automatically
* Packages produced from nodejs.src have Provides: stream(nodejs)
stream(nodejs:9) and Conflicts: stream(nodejs) so that it is
explicitly not possible to install 9 and 10 at the same time
* If desired, packages can depend on a specific stream via Requires:
stream(nodejs:10) without actually depending on nodejs (this requires
some small piece of code in libsolv)
* In the very similar way, user can lock themselves to a specific
stream by writing some conf file which DNF would read (if point above
is implemented, about just tens of lines of the code in libdnf, or
even libsolv can be teached about that as well)
* DNF can be teached about these special things so that you can
automatically swap conflicting dependencies, but lock yourself to some
streams of a package
* All standard Conflicts/Requires/Obsoletes/… will simply work
* With side tags on demand it is now much easier
* Mass rebuild scripts will be teached about stream branches and will
build packages properly
* After branching, there will be a script which untags all packages
which should not be supported in the new release
* fedpkg will be teached about stream branches and will show which
branches build where, so that maintainers can easily maintain them
* Packaging guidelines should be adopted to accept conflicting
packages and tooling should be improved to show the conflicts and how
to resolve them
* fedora-release will have Suggests: stream(nodejs:10) so that when
user types dnf install nodejs, for example nodejs10 would be picked up
(instead of nodejs12)
* Some macros can be added to generate virtual package with "default
stream", so that there will be actual nodejs package depending on
nodejs12 if that would be default in given Fedora release
* Going further, I would extend Koji with fedora plugin which would
deal with the build submission instead of having this logic on clients
so that all people get same result
===
Now let me quote Matthew Miller with the list of requirements and
answer how we achieve them.
1. Users should have alternate streams of software available.
I think this is achieved with what I have said above. We will ship
nodejs9, nodejs10 at the same time.
2. Those alternate streams should be able to have different lifecycles.
nodejs 9 and 10 can automatically build for all distros until EOL
(which would be stored somewhere). EOL-date aware tooling (fedpkg)
would not build for excluded versions of distros and build for distros
where EOL of distro is further than EOL of component.
3. Packaging an individual stream for multiple outputs should be
easier than before.
As I wrote above, we will have one nodejs rpm repo with multiple
branches (aka streams) and no name mangling needed. fedpkg build will
spawn builds for all releases matching criteria (EOL date, excluded
distributions).
===
This is not the exact approach we have tried back in the days, but it
is very similar to that. Unfortunately I did not save any documents
from those times but Adam or Brian probably still can find them (since
they are RH internal).
4 years
Fedora 32 Self-Contained Change proposal: Rebase apt package from
apt-rpm to Debian's apt
by Ben Cotton
https://fedoraproject.org/wiki/Changes/Move_apt_package_from_RPM_to_DPKG_...
== Summary ==
Currently the apt package in Fedora actually installs apt-rpm,
starting with Fedora 32 it will provide the regular apt software
backed by DPKG.
== Owner ==
* Name: [[User:dridi| Dridi Boukelmoune]], [[User:ngompa | Neal Gompa]]
* Email: dridi(a)fedoraproject.org, ngompa13(a)gmail.com
== Detailed Description ==
The apt package in Fedora does not ship the mainline apt software from
Debian, but rather the apt-rpm fork instead. This allows a user to
copy and paste apt or apt-get commands often found in "Linux"
tutorials. This will usually work, apt-rpm will resolve dependencies
from the Yum/DNF repositories and since our package naming guidelines
often lead to the same package names as apt-based distributions like
Debian and Ubuntu.
The apt-rpm software is dead upstream and doesn't support rich
dependencies or modules. It also has known vulnerabilities and
according to its author other bugs that are never going to be fixed.
== Benefit to Fedora ==
By switching the Fedora apt package from apt-rpm to regular apt we
move from a dead to a living upstream. We also close security holes
and introduce a critical dependency for more packages from the DPKG
ecosystem. It is already possible to build Deb packages in Fedora,
including with pbuilder, an equivalent for mock in the DPKG ecosystem,
however pbuilder uses debootstrap to provision a build environment.
While we may lose the ability to "apt-get install" Fedora packages
from the command line, we also open the gate for sbuild, another mock
equivalent to build Debs in a clean environment. This change offers
more options to target Debian and derivative systems without leaving
the Fedora comfort zone.
== Scope ==
* Proposal owners: re-review of the apt package with the proper
upstream ([https://bugzilla.redhat.com/show_bug.cgi?id=1764813
RH#1764813]), and optionally more dependent packages.
* Other developers: N/A (not a System Wide Change)
* Release engineering: N/A (not needed for this Change)
* Policies and guidelines: As apt would conflict with DNF for the host
system, we may want to ship it without pre-configured repositories.
* Trademark approval: N/A (not needed for this Change)
== Upgrade/compatibility impact ==
Any user actively relying on apt-rpm will lose functionality that
cannot be replaced. Because apt-rpm's version is much lower than the
current apt version, this change will follow the natural upgrade path.
== How To Test ==
If sbuild is packaged in time for the beta, performing builds with
sbuild should be enough to confirm that apt was able to provision a
build root.
== User Experience ==
Anyone used to paste apt-get commands in a terminal will no longer be
able to install or remove Fedora packages this way.
On the other hand anyone needing regular apt tooling will be able to
work with it directly from Fedora.
== Dependencies ==
Apt shouldn't bring more dependencies, it will be the dependency for
more packages from the DPKG ecosystem.
== Contingency Plan ==
* Contingency mechanism: Simply retire apt (apt-rpm)
* Contingency deadline: N/A (not a System Wide Change)
* Blocks release? N/A (not a System Wide Change)
* Blocks product? N/A
== Documentation ==
Once installed, apt ships multiple manual pages available in several
languages. There will no longer be any references in the shipped apt
package documentation of handling RPMs.
== Release Notes ==
The apt package has been rebased from apt-rpm to Debian's apt. This
means that apt no longer supports handling RPMs or managing RPM-based
systems. Please use dnf for software management of RPM-based systems
and containers.
--
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis
4 years
Re: do not remove arpack package from Fedora
by Miro Hrončok
On 29. 11. 19 2:53, Conrad Sand wrote:
> Hi Miro,
>
> Please _do not_ remove arpack and arpack-devel.
Sure, please rebuilt it. Orion has started to work on it in
https://src.fedoraproject.org/rpms/arpack/pull-request/1
> A lot of other packages depend on that.
At least 49 according to the report, yes. That's why I have sent it out, so the
dependent package maintainers have a chance to fix it.
> Removing arpack doesn't make any sense.
Removing packages that haven't been built for certain number of releases is a
Fedora policy described in:
https://docs.fedoraproject.org/en-US/fesco/Fails_to_build_from_source_Fai...
It is not my personal quirk.
If you don't agree with the policy itself, I suggest you start having a serious
discussion about the policy on devel mailing list (CCed). Last time I tried to
discuss the policy on the list in this thread:
https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.o...
My intent was to make the policy less strict and give packagers some room.
If the intent was not accomplished enough, I am still open to hear more suggestions.
If you don't disagree with the policy but thing that it should not apply to
arpack, please, discuss that to. Simply saying "removing arpack doesn't make any
sense" without providing all the necessary context is not helpful.
> If you remove arpack, you might as well remove all serious scientific
> software from Fedora.
I don't understand this statement. If we remove arpack we might as well remove
the 49 packages. That hardly all serious scientific software in Fedora.
I realize that there are some high impact packages. That's why we should
together strive to fix the build failure and avoid disruption.
> Rather than providing the sole reason for the removal as "fail to
> build from source", shouldn't the first effort be towards fixing the
> affected package? You break it, you fix it, no?
My effort is to raise the awareness about he failure. Despite my large effort, I
cannot possibly fix all the build failures in Fedora. If I broke arpack, I am
terribly sorry, but I am not aware of that.
The failure is tracked in https://bugzilla.redhat.com/show_bug.cgi?id=1734942
Yet there was no movement until this e-mail. In a way, the e-mail helped.
> Throwing out arpack is an absolute overkill, and to be perfectly
> honest, a boneheaded and extremely shortsighted proposal.
My intentions are to raise the awareness of the issue. Throwing anything away
will only happen to packages where nobody cares about them. Clearly, you care
about arpack and that is appreciated.
There are 2+ months now to do one of the following:
- make it build
- change the policy
- exempt arpack from the policy
I can help with the second two, if there are good reasons given and rest of the
contributors agree. Orion is helping with the first.
--
Miro Hrončok
--
Phone: +420777974800
IRC: mhroncok
4 years
Is 50+ RPM Subpackages too extreme?
by Chris
Hi guys,
I just wanted to poll you for some advice. My notification tool I maintain
supports more than 50+ services now, but the only package isolation I do
within 2 RPMs. One for the actual CLI (for admin's who want to use it) and
the other is for the backend library (for Devs). I only ask because each
supported service is very modular.
I kind of like the way nagios-plugins breaks apart it's check_scripts into
many sub-packages, but 50+ subpackages seems a bit extreme... or is it? It
certainly seems like a bit of a nightmare to maintain; it would be one very
large .spec file.
You can see the directory structure here on GitHub:
https://github.com/caronc/apprise
Effectively every single file in "apprise/plugins/Notify*.py" is it's own
plugin-able module. You can add/remove content into here and the tool
adapts. Thus the sub-packages would only include 1 file per RPM.
Is it advisable to go this route? I presume there is no easy way to
transition without breaking users existing setup? I don't know what the d/l
stats are; so there may not be a large enough audience to even need to
worry about this?
What are your thoughts and/or advice?
4 years
Review swap: bcftools
by Jun Aruga
* Review Request: bcftools - Tools for genomic variant calling and
manipulating VCF/BCF files
https://bugzilla.redhat.com/show_bug.cgi?id=1774741
Bio science tool. C language. No sub package.
This new package is necessary to upgrade current samtools 0.1 to 1.9.
Because some functions in samtools 0.X had been split to bcftools.
Thanks.
--
Jun | He - His - Him
4 years
