On Tue, Dec 8, 2020 at 4:19 PM Pete Biggs pete@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.