[Base] Base Design WG agenda meeting August, 31st 2015 14:15 UTC on #fedora-meeting-2

[Simo Sorce]

On Mon, 2015-08-31 at 10:18 -0700, Brendan Conoboy wrote:
> On 08/31/2015 08:17 AM, Harald Hoyer wrote:
> [snip]
> > Minutes:
> > <http://meetbot.fedoraproject.org/fedora-meeting-2/2015-08-31/fedora_base_design_working_group.2015-08-31-14.15.html>
> > Minutes (text):
> > <http://meetbot.fedoraproject.org/fedora-meeting-2/2015-08-31/fedora_base_design_working_group.2015-08-31-14.15.txt>
> > Log:
> > <http://meetbot.fedoraproject.org/fedora-meeting-2/2015-08-31/fedora_base_design_working_group.2015-08-31-14.15.log.html>
> 
> For today's meeting we didn't really use zodbot minute keeping 
> features, so in the interest of sparking some discussion I'd like to 
> recap.
> 
> At Flock 2015 there was a 2 hour session on the subject of rings which 
> are basically policy zones inhabited by packages.  Right now fedora 
> packaging has 1 policy, so the entire OS is in a single ring. 
> Creating more rings means creating more policies.  By doing this 
> Fedora can become adopt the flexible to appeal to diverse development 
> communities and thus grow.  The general consensus at Flock was that 
> Environments and Stacks should take the lead in helping to define new 
> rings, and especially how the rings interact.  As a side note, 
> everyone agreed the word "rings" breaks down the further you get away 
> from the center, but nobody has come up with something better yet 
> (Venns? Blobs? Zones?).  A week or so ago, a small Environments and 
> Stacks meeting took place where it was generally agreed that the Base 
> working group was the right place to define Ring 0.  That brings us to 
> this morning's BaseWG meeting.  I talked a lot so here is a rough 
> recap integrating a few of the questions and comments people had (Do 
> read the log if you have time!)
> 
> Right now the Fedora distribution is 1 ring, let's call it ring 1. 
> The distribution contains an operating system and numerous 
> applications that run on that operating system.  When we talk about 
> defining ring 0 we're really talking about distinguishing between the 
> operating system and the applications that run on top of it.
> 
> We want to go from this:
> 
> Ring 1: The Fedora Distribution
> 
> To this:
> 
> The Fedora Distribution:
> Ring 0: The Linux Operating System
> Ring 1: The Applications and Stacks
> 
> It seems quite modest, but working through the details on what this 
> means is hard.  What is an operating system in the Linux context? 
> Ring 0 will likely have the strictest set of policies of all the 
> rings, so we want to keep it as small as possible, but it is more than 
> a minimal install.  These are the traits of rings in general and ring 
> 0 in particular as I see it:
> 
> 1. Ring 0 is a repository of rpm packages built in koji.
> 
> 2. Ring 0 contains, but is not limited to, the minimal install of 
> packages to go from Power On to a login prompt.
> 
> 3. Ring 0 passes repoclosure on its own (Packages listed as hard 
> "Requires" in a ring 0 spec file are themselves are implicitly ring 0).
> 
> 4. Ring 0 is not self hosting.  Packages listed in "BuildRequires" do 
> not need to be members of Ring 1.  This isn't ideal, but it's a 
> practical consideration.
> 
> 5. Ring membership is at the source package level, not the binary 
> package.  If one source package's binary/noarch sub-package is in ring 
> 0, all sub-packages are in ring 0.

Can you elaborate more on this point (5) ?

I can totally see how a package may be critical and therefore deserve to
be in ring 0 and yet have optional features in terms of subpackages that
are not necessarily ring 0.
For example some library that offers optionally bindings for somewhat
rarely used languages (say ocaml). The subpackages for those bindings
shouldn't necessarily be ring 0.

Or did I misunderstand the point ?

> 6. Ring 0 contains the minimal libraries that define the OS API/ABI, 
> such as glibc.  This probably happens implicitly by #3, repoclosure.
> 
> 7. Ring 0 contains the tools needed to update existing packages and 
> install new packages.
> 
> That's the starting point, but it is by no means comprehensive.  The 
> OS probably provides specific services beyond the ability to login, 
> for instance.  Which styles of boot are supported?  Where does 
> installation infrastructure like anaconda land?  This is equal parts 
> philosophy and practicality.  Also, policies for ring 0 may differ 
> from what Base has previously adopted: Do we create a ring 0 minimal 
> compose since we already need to check repoclosure?  This might be a 
> great way to refactor primary/secondary such that we can gracefully 
> transition i686 down and secondary arches up.  Lots of opportunities, 
> much to consider.
> 
> -- 
> Brendan Conoboy / Red Hat, Inc. / blc at redhat.com


-- 
Simo Sorce * Red Hat, Inc * New York