Re: [RFC PATCH 14/15] gitlab-ci: Allow forks to use different set of jobs

[Philippe Mathieu-Daudé]

+Stefan/Peter

On 4/19/21 12:59 PM, Thomas Huth wrote:
> On 19/04/2021 12.51, Daniel P. Berrangé wrote:
>> On Mon, Apr 19, 2021 at 12:48:25PM +0200, Thomas Huth wrote:
>>> On 19/04/2021 12.36, Daniel P. Berrangé wrote:
>>>> On Mon, Apr 19, 2021 at 12:20:55PM +0200, Thomas Huth wrote:
>>>>> On 19/04/2021 12.10, Erik Skultety wrote:
>>>>>> On Mon, Apr 19, 2021 at 10:40:53AM +0100, Daniel P. Berrangé wrote:
>>>>>>> On Mon, Apr 19, 2021 at 01:34:47AM +0200, Philippe Mathieu-Daudé
>>>>>>> wrote:
>>>>>>>> Forks run the same jobs than mainstream, which might be overkill.
>>>>>>>> Allow them to easily rebase their custom set, while keeping using
>>>>>>>> the mainstream templates, and ability to pick specific jobs from
>>>>>>>> the mainstream set.
>>>>>>>>
>>>>>>>> To switch to your set, simply add your .gitlab-ci.yml as
>>>>>>>> .gitlab-ci.d/${CI_PROJECT_NAMESPACE}.yml (where
>>>>>>>> CI_PROJECT_NAMESPACE
>>>>>>>> is your gitlab 'namespace', usually username). This file will be
>>>>>>>> used instead of the default mainstream set.
>>>>>>>
>>>>>>> I find this approach undesirable, because AFAICT, it means you have
>>>>>>> to commit this extra file to any of your downstream branches that
>>>>>>> you want this to be used for.  Then you have to be either delete it
>>>>>>> again before sending patches upstream, or tell git-publish to
>>>>>>> exclude the commit that adds this.
>>>>>>>
>>>>>>> IMHO any per-contributor overhead needs to not involve committing
>>>>>>> stuff to their git branches, that isn't intended to go upstream.
>>>>>>
>>>>>> Not just that, ideally, they should also run all the upstream
>>>>>> workloads before
>>>>>> submitting a PR or posting patches because they'd have to respin
>>>>>> because of a
>>>>>> potential failure in upstream pipelines anyway.
>>>>>
>>>>> It's pretty clear that you want to run the full QEMU CI before
>>>>> submitting
>>>>> patches to the QEMU project, but I think we are rather talking
>>>>> about forks
>>>>> here that are meant not meant for immediately contributing to upstream
>>>>> again, like RHEL where we only build the KVM-related targets and
>>>>> certainly
>>>>> do not want to test other things like CPUs that are not capable of
>>>>> KVM, or a
>>>>> branch where Philippe only wants to check his MIPS-related work during
>>>>> development.
>>>>> For contributing patches to upstream, you certainly have to run the
>>>>> full CI,
>>>>> but for other things, it's sometimes really useful to cut down the CI
>>>>> machinery (I'm also doing this in my development branches manually
>>>>> some
>>>>> times to speed up the CI), so I think this series make sense, indeed.
>>>>
>>>> For a downstream like RHEL, I'd just expect them to replace the main
>>>> .gitlab-ci.yml entirely to suit their downstream needs.
>>>
>>> But that still means that we should clean up the main .gitlab-ci.yml
>>> file
>>> anyway, like it is done in this series, to avoid that you always get
>>> conflicts in this big file with your downstream-only modifications.
>>> So at
>>> least up to patch 11 or 12, I think this is a very valuable work that
>>> Philippe is doing here.
>>
>> I don't see a real issue with downstream conflicts. They'll just
>> periodically pick a release to base themselves off and change once
>> every 6 months or more.
> 
> It's not only downstream distros that rebase every 6 month. Like
> Philippe, I'm sometimes hacking my .gitlab-ci.yml of my development
> branch to speed up the CI during my development cycles (i.e. I'm
> removing the jobs that I do not need). And I'm regularly rebasing my
> development branchs. Conflicts in .gitlab-ci.yml are then always
> painful, so a leaner main .gitlab-ci.yml file would be helpful for me,
> too, indeed.

Not sure if following up this thread or start a new one, but I got
blocked again from Gitlab, tagged as a crypto miner for running QEMU
CI...
[1]
https://about.gitlab.com/handbook/support/workflows/investigate_blocked_pipeline.html#trends--high-priority-cases

I pushed 5 different branches to my repository in less than 1h,
kicking 580 jobs [*].

I didn't try to stress Gitlab, it was a simple "one time in the month
rebase unmerged branches, push them before respining on the mailing
list".

I'm considering changing my workflow:
- not push more than 2 branches per hour (I know 3/h works, so choose
  a lower number, as we want to add more tests).
- merge multiple branches locally and push the merged result and
  bisect / re-push on failure
- run less testing
- do not run testing

This sounds counter productive and doesn't scale to a community of
contributors asked to use Gitlab.

So far I don't have better idea than this series.

Who is interested in sending patches to improve our workflow?

Thanks,

Phil.

[*] NB I have 3 extra runners added to my namespace, but it didn't
help, as per [1] I got blocked by reaching an API rate limit.