CentOS - Dec 2020 - https://blog.centos.org/2020/12/future-is-centos-stream/

On Tue, 2020-12-08 at 17:54 -0500, Matthew Miller wrote:
> On Tue, Dec 08, 2020 at 03:15:17PM +0000, Pete Biggs wrote:
> > "CentOS will become the developer playground"
> 
> This one is categorically not the case. Even Fedora isn't a developer
> playground. Everything landing in CentOS Stream is actually *planned* (with
> emphasis intentional) to go in a future RHEL release.
It's all the talk of SIGs and developing and testing and that Stream
will be the centerpiece of that. That's what I meant. 
> 
> Previously, all the development around RHEL releases was done in secret, in
> the Red Hat black box. Now it's out of the box and can be watched.
There may
> be some launch pains, but I expect the average quality of an update hitting
> CentOS Stream to be very high.
I don't get that from the documents released today.  If Stream is *not*
a test-bed, then surely the code that appears in Stream must be fully
formed in secret behind the scenes first. Yes, it will appear piecemeal
rather than in one big chunk, but it has been categorically denied that
Stream is not a RHEL 8.n+1 beta and is more a RHEL 8.n+1 RC/rolling
release. 


I think what a lot of people are concerned about is the rolling-release
aspect of this. There will be no definitive versioning of CentOS in the
future - all you will be able to say is "fully updated" and it
won't be
possible to slot a CentOS system in to exactly match a RHEL version.
Will third party RPMs built against RHEL 8.x be installable on a CentOS
8 Stream system? The answer is surely "it depends", but there are a
lot
of hardware vendors that target drivers to RHEL releases, which may
well make CentOS non-viable for hardware that doesn't have drivers
built in to the kernel.

I suspect that for a large proportion of scenarios Streams will be
perfectly OK. But we still get software/instruments that specifically
say "only RHEL 7.4" or something like that (yes, it's a support
nightmare).  

P.

On 12/8/20 6:18 PM, Pete Biggs wrote:
> On Tue, 2020-12-08 at 17:54 -0500, Matthew Miller wrote:
>> On Tue, Dec 08, 2020 at 03:15:17PM +0000, Pete Biggs wrote:
> 
>>> "CentOS will become the developer playground"
>>
>> This one is categorically not the case. Even Fedora isn't a
developer
>> playground. Everything landing in CentOS Stream is actually *planned*
(with
>> emphasis intentional) to go in a future RHEL release.
> 
> It's all the talk of SIGs and developing and testing and that Stream
> will be the centerpiece of that. That's what I meant. 
> 
>>
>> Previously, all the development around RHEL releases was done in
secret, in
>> the Red Hat black box. Now it's out of the box and can be watched.
There may
>> be some launch pains, but I expect the average quality of an update
hitting
>> CentOS Stream to be very high.
> 
> I don't get that from the documents released today.  If Stream is *not*
> a test-bed, then surely the code that appears in Stream must be fully
> formed in secret behind the scenes first. Yes, it will appear piecemeal
> rather than in one big chunk, but it has been categorically denied that
> Stream is not a RHEL 8.n+1 beta and is more a RHEL 8.n+1 RC/rolling
> release. 
> 
> 
> I think what a lot of people are concerned about is the rolling-release
> aspect of this. There will be no definitive versioning of CentOS in the
> future - all you will be able to say is "fully updated" and it
won't be
> possible to slot a CentOS system in to exactly match a RHEL version.
> Will third party RPMs built against RHEL 8.x be installable on a CentOS
> 8 Stream system? The answer is surely "it depends", but there are
a lot
> of hardware vendors that target drivers to RHEL releases, which may
> well make CentOS non-viable for hardware that doesn't have drivers
> built in to the kernel.
> 
> I suspect that for a large proportion of scenarios Streams will be
> perfectly OK. But we still get software/instruments that specifically
> say "only RHEL 7.4" or something like that (yes, it's a
support
> nightmare).  
> 
It is not the same as Rawhide is all I am saying.

It is based on the current release and it is being modified for some reason.

That modification can be a bugfix from a reported bug, it can be an
enhancement for a given package or it can be a security update.

Each of these updates will be rolled in one at a time.

It is what will eventually become the next rhel source code in a few
months for the next point release.

Only you will know if this will work for your situation.

We do have CI testing, which will be beefed up to be similar to the
testing RHEL actually does right now before release of packages for the
'released version' of RHEL.

Will bugs get though .. sure, they do now into RHEL.

But I will absolutely say that the things they are rolling into RHEL 8.4
in a few months are not inherently less stable or less secure or
whatever else you want to call it .. when compared to other Linux distros.

The process that Debian would use to roll in bug fixes or Ubuntu would
use to roll in bug fixes would not be significantly better or more
stable or more secure.

On Tue, Dec 8, 2020 at 4:19 PM Pete Biggs <pete at biggs.org.uk> wrote:
> On Tue, 2020-12-08 at 17:54 -0500, Matthew Miller wrote:
> > On Tue, Dec 08, 2020 at 03:15:17PM +0000, Pete Biggs wrote:
>
> > > "CentOS will become the developer playground"
> >
> > This one is categorically not the case. Even Fedora isn't a
developer
> > playground. Everything landing in CentOS Stream is actually *planned*
> (with
> > emphasis intentional) to go in a future RHEL release.
>
> It's all the talk of SIGs and developing and testing and that Stream
> will be the centerpiece of that. That's what I meant.
>
I don't know if I'd call SIGs a playground, but they're certainly an
important venue for communities to explore variations.

> > Previously, all the development around RHEL releases was done in
secret,
> in
> > the Red Hat black box. Now it's out of the box and can be watched.
There
> may
> > be some launch pains, but I expect the average quality of an update
> hitting
> > CentOS Stream to be very high.
>
> I don't get that from the documents released today.  If Stream is *not*
> a test-bed, then surely the code that appears in Stream must be fully
> formed in secret behind the scenes first. Yes, it will appear piecemeal
> rather than in one big chunk, but it has been categorically denied that
> Stream is not a RHEL 8.n+1 beta and is more a RHEL 8.n+1 RC/rolling
> release.
>
I think maybe some of the nervousness about CentOS Stream comes from RHEL
seeming opacity on its development model.  As one of the architects of our
development process I'd be happy to field questions.  I'll start by
making
a two points in case they're in any way unclear:

1. Everything that goes into RHEL lands upstream first, then the patches
are backported into the RHEL releases.
2. Most of the work we do or plan on doing is in bugzilla.redhat.com.  If
you go into the RHEL8 product queue today and file a bug you'll see
"CentOS
Stream" as a "Version" where an issue is encountered.

I think what a lot of people are concerned about is the
rolling-release
> aspect of this. There will be no definitive versioning of CentOS in the
> future - all you will be able to say is "fully updated" and it
won't be
> possible to slot a CentOS system in to exactly match a RHEL version.
> Will third party RPMs built against RHEL 8.x be installable on a CentOS
> 8 Stream system? The answer is surely "it depends", but there are
a lot
> of hardware vendors that target drivers to RHEL releases, which may
> well make CentOS non-viable for hardware that doesn't have drivers
> built in to the kernel.
>
Generally if they follow the ABI guidelines I would expect it to work.
Those are here: https://access.redhat.com/articles/rhel8-abi-compatibility

For loadable kernel modules there's a kernel ABI.

> I suspect that for a large proportion of scenarios Streams will be
> perfectly OK. But we still get software/instruments that specifically
> say "only RHEL 7.4" or something like that (yes, it's a
support
> nightmare).

It's regrettable when an ISV gets fixated on minor release versions and
won't recognize forward compatibility.  This is generally more of a matter
of policy rooted in legacy than a technical limitation.

-- 
Brendan Conoboy / Linux Project Lead / Red Hat, Inc.