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Wireshark-dev: Re: [Wireshark-dev] Proposed Gerrit workflow (was: Re: Notes from Sharkfest '13)

From: Bálint Réczey <balint@xxxxxxxxxxxxxxx>
Date: Mon, 24 Jun 2013 13:38:00 +0100
Hi Michael,

2013/6/24 Michael Tuexen <Michael.Tuexen@xxxxxxxxxxxxxxxxx>:
> On Jun 23, 2013, at 8:58 PM, Bálint Réczey <balint@xxxxxxxxxxxxxxx> wrote:
>
>> Hi,
>>
>> 2013/6/22 Marc Petit-Huguenin <marc@xxxxxxxxxxxxxxxxxx>:
>>> -----BEGIN PGP SIGNED MESSAGE-----
>>> Hash: SHA256
>>>
>>> On 06/22/2013 09:43 AM, Bálint Réczey wrote:
>>>> Hi Marc,
>>>>
>>>> 2013/6/22 Marc Petit-Huguenin <marc@xxxxxxxxxxxxxxxxxx>:
>>>>> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256
>>>>>
>>>>> On 06/22/2013 03:47 AM, Bálint Réczey wrote:
>>>>>> Hi All,
>>>>>>
>>>>>> 2013/6/21 Marc Petit-Huguenin <marc@xxxxxxxxxxxxxxxxxx>:
>>>>>>> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256
>>>>>>>
>>>>>>> On 06/20/2013 04:52 PM, Guy Harris wrote:
>>>>>>>>
>>>>>>>> On Jun 20, 2013, at 2:58 PM, Marc Petit-Huguenin
>>>>>>>> <marc@xxxxxxxxxxxxxxxxxx> wrote:
>>>>>>>>
>>>>>>>>> On 06/20/2013 02:17 PM, Gerald Combs wrote:
>>>>>>>>>
>>>>>>>>>> Advantates: - I'm not sure that an in-house equivalent (e.g.
>>>>>>>>>> Gerrit plus a private repository) would be better than what
>>>>>>>>>> Github offers.
>>>>>>>>>
>>>>>>>>> Yes, Gerrit is better than github:
>>>>>>>>
>>>>>>>> Presumably you mean "Gerrit plus a private repository is better
>>>>>>>> than github", as Gerrit, as far as I can tell, is just software
>>>>>>>> that works with a Git repository.
>>>>>>>
>>>>>>> Yes, although managing repositories being what Gerrit do, Gerrit
>>>>>>> without a least one repository would be a very boring application.
>>>>>> :-)
>>>>>>
>>>>>> I have started describing a Gerrit based workflow which IMO would fit
>>>>>> to the project at http://wiki.wireshark.org/Development/Workflow .
>>>>>> Please check it and share your opinion.
>>>>>>
>>>>>
>>>>> "Code is building and tests are passing on all platforms. (Tests
>>>>> automatically start when at least one Core Developer gives +1 or +2 to
>>>>> prevent overloading or cracking the build servers.)"
>>>>>
>>>>> Why do not build and test all patchsets submitted?  Is that a limitation
>>>>> of the build servers?  Having Jenkins automatically verify your patchset
>>>>> is IMO one of the nice feature of Gerrit, and it will lower the workload
>>>>> of core devs if building and testing are done before they start looking
>>>>> at the patchset.
>>>> Build can be triggered by patchset submissin, too, but it would require
>>>> more build server resources. Usually not the first version of the
>>>> changeset will be accepted especially from new contributors and this means
>>>> more builds.
>>>
>>> My view is the opposite: New contributors patchsets will probably be rejected
>>> anyway (does not build, does not pass test, etc...), so having the system
>>> doing that lowers the burden on core developers, who they can focus on more
>>> high level problems.
>>>
>>>> Note that Core Developers would not have to wait since they can give +1 for
>>>> their own changesets.
>>>>
>>>> The other reason behind requiring a +1 from someone we trust is that
>>>> otherwise it would be easy to prepare a changeset which does unspeakable
>>>> things to the build servers which we don't want to happen. Without
>>>> requiring +1 we would have to prepare build systems to cope with malicious
>>>> commits.
>>>
>>> That is a good point (basically because of the halting problem).  But builds
>>> are done in isolation (i.e a git clone is done each time), so apart using too
>>> much resources or never ending, there is no harm that can be done to the
>>> infrastructure.  And there is a Jenkins plugin to abort a build if it is stuck.
>> I was concerned about using the buildbots for attacking other systems, too,
>> but all of those threats can be handled and we have time for setting
>> up build bots
>> properly.
>>
>> I have updated the proposal to start tests for every change and allow
>> Code Devs to
>> bypass peer review.
>>
>> Comments are still welcome. :-)
> Dear all,
>
> hmm. From a process point of view: How long do I need to wait until condition 2
> is fulfilled. For me this looks like a race condition. If I get a 2+ before a 2-
> it gets in, if it is the other way, it doesn't...
Devs coming late can discuss the change they don't agree with, like now. ;-)

>
> Anyway... I'm not sure if this process really improves wireshark as a project.
> It all depends on others willing to to do peer reviews. In an industrial environment,
> you can force developers to do that. In an open source community, you can't.
> I'm not saying, that the peer reviews won't be done, but I'm not sure if they will.
We already have code review in our process but it is performed in
bugzilla or on the
mailing lists. Gerrit will give a better interface for those.
We already checked interesting changes after commits, and Gerrit will
help that, too.

I've just checked LibreOffice's and Android's Gerrit installation and
they seem to
be making progress on reviews and
https://www.google.com/search?q=open+source+projects+per+review
also lists several articles about peer-reviews performed in Open Source projects
which make me think that we could do it, too.

>
> The current process puts responsibility on the core developer who commits a
> change. Personally, I don't think it is bad if this breaks the build on
> some buildbot, I only this it is bad if the committer doesn't care. This
> worked out pretty well in the past, I think. I only run the head version
> of wireshark and can usually build it (thanks to the Mac OS X buildbots).
> If a core developer didn't want to take responsibility for a patch, he
> could contact others to get feedback on questions. This also worked in
> the past since you contacted people who also are interested in the subject.
I'm generally satisfied with the quality of trunk and I'm proud to be
part of the project.
I also think if we could break trunk even less often, it would be even better
and Gerrit would help that and would also help discussing the patches.

> The same responsibility applies for changes being compiled by the
> buildbots. Each such change comes from a core developer. I'm hesitating
> to allow an arbitrary patch to compile on the buildbots where we have
> no one being responsible for it in any way. Some of the buildbots run
> older software, some of them are not hardened in any way.
If all the buildbots are running a newly cloned VM and limits network usage
of the VM, I think we can be safe.

>
> Does someone have experience with an open source project comparable to
> Wireshark requesting peer review? Linux wants patches to be signed, but
> they have maintainers, Mozilla/Firefox has payed developers...
https://www.google.com/search?q=open+source+projects+per+review lists a
few in addition to the two I listed in the proposal.

>
> Don't get me wrong: I'm against introducing more procedural constraints,
> if it helps wireshark as a project. I just think that the current situation
> isn't too bad and I'm not sure how to make sure non-trivial peer reviews
> get done...
I hope we could put together a pleasant wokflow which helps the project.
I think we see Git bringing in a lot of improvements but with Git can't come
without changing the workflow a bit. Simply because Git is way faster than
Subversion and it is too easy to push a lot of things to master accidentally.
There needs to be someone (Linux's model) or something (Gerrit) preventing
that.

I think the proposed workflow with Gerrit would fit the project's way of doing
development with minimal changes to the current workflow.

Cheers,
Balint