Open Stack

----- Original Message -----
> From: "Monty Taylor" <mordred at inaugust.com>
> To: openstack at lists.launchpad.net
> Sent: Thursday, June 28, 2012 11:13:28 AM
> Subject: Re: [Openstack] Jenkins vs SmokeStack tests & Gerrit merge blockers
> 
> 
> 
> On 06/28/2012 07:32 AM, Daniel P. Berrange wrote:
> > Today we face a situation where Nova GIT master fails to pass all
> > the libvirt test cases. This regression was accidentally introduced
> > by the following changeset
> > 
> >    https://review.openstack.org/#/c/8778/
> > 
> > If you look at the history of that, the first SmokeStack test run
> > fails with some (presumably) transient errors, and added negative
> > karma to the change against patchset 2. If it were not for this
> > transient failure, it should have shown the regression in the
> > libvirt test case. The libvirt test case in question was one that
> > is skipped, unless libvirt is actually present on the host running
> > the tests. SmokeStack had made sure the tests would run on such a
> > host.
> > 
> > There were then further patchsets uploaded, and patchset 4 was
> > approved for merge. Jenkins ran its gate jobs and these all passed
> > successfully. I am told that Jenkins will actually run the
> > unittests
> > that are included in Nova, so I would have expected it to see the
> > flawed libvirt test case, but it didn't. I presume therefore, that
> > Jenkins is not running on a libvirt enabled host.
> 
> Kind of - it's sadly more complex than that ...
> 
> > The end result was that the broken changeset was merged to master,
> > which in turns means any other developers submitting changes
> > touching the libvirt area will get broken tests reported that
> > were not actually their own fault.
> > 
> > This leaves me with the following questions...
> > 
> >  1. Why was the recorded failure from SmokeStack not considered
> >     to be a blocker for the merge of the commit by Gerrit or
> >     Jenkins or any of the reviewers ?
> >
> >  2. Why did SmokeStack not get re-triggered for the later patch
> >     set revisions, before it was merged ?
> 
> The answer to 1 and 2 is largely the same - SmokeStack is a community
> contributed resources and is not managed by the CI team. Dan Prince
> does
> a great job with it, but it's not a resource that we have the ability
> to
> fix should it start messing up, so we have not granted it the
> permissions to file blocking votes.

I would add that if anyone else is interested in collaborating on making SmokeStack better I'm more than happy to give access. Its all open source and has been since Cactus.

As is now SmokeStack can can cast a -1 vote and hopefully this is proving to be useful. I'm open to suggestions.


> 
> The tests that smokestack runs could all be written such that they
> are
> run by jenkins.

I actually put in quite a bit of work to maintain an openstack_vpc job on Jenkins post-Cactus. When we talked about gating on this job at the Diablo conference the idea didn't seem to get very far... I kind of saw that as the end of the line for maintaining an openstack_vpc job and eventually it went away. Not sure who deleted it, but anyway.

The way I see it there is value in both testing systems. Rather than complaining about why one system exists and/or doesn't port its tests to the other.... why don't we build on each others strengths. Seeing a green "verified +1" from both Jenkins and SmokeStack on a review should be very encouraging... and if one of the two systems fails it might require further investigation.


> The repos that run the jenkins tests are all in git
> and
> managed by openstack's gerrit. If there are testing profiles that it
> runs that we as a community value and want to see part of the gate,
> anyone is welcome to port them.
> 
> >  3. Why did Jenkins not ensure that the tests were run on a libvirt
> >     enabled host ?
> 
> This is a different, and slightly more complex. We run tests in
> virtualenvs so that the process used to test the code can be
> consistently duplicated by all of the developers in the project. This
> is
> the reason that we no longer do ubuntu package creation as part of
> the
> gate - turns out that's really hard for a developer running on OSX to
> do
> locally on their laptop - and if Jenkins reports an blocking error in
> a
> patch, we want a developer to be able to reproduce the problem
> locally
> so that they can have a chance at fixing it.

The ability for developers to test things locally is very important. For that matter SmokeStack all started with a project called openstack_vpc, a project to spin up groups of cloud servers installed with the latest OpenStack code. A developer can use a project like openstack_vpc to spin up a set of servers in the cloud which builds and installs custom built packages for a set of Git URLs. So essentially the underpinnings of SmokeStack *can* all be done from a local machine just like they run from the UI.

There is also value in testing things differently in ways which may not be easy for all developers to reproduce. Take XenServer for example... not every developer has access to a machine which can spin up a mini XenServer cloud. Is there value in running upstream tests on XenServer? I think so...

What about running OpenStack with PostgreSQL and MySQL, Rabbit and Qpid? What I'm trying to do with SmokeStack is add value to our testing matrix so that some of the things we aren't automatically testing elsewhere get some coverage.

Reproducability is important... but the way I see it if everyone always ran tests with exactly the same flags, or in the same environments we might not find some things.

And where a developer can't reproduce something locally what I've done is give them direct access to a box running a SmokeStack job so they can troubleshoot it directly.


> 
> Problem arise in paradise though. libvirt being one of them. It's not
> possible to install libvirt into a virtualenv, because it's a
> swig-based
> module built as part of the libvirt source itself. One of the
> solutions
> to this is to allow the testing virtual environments to use packages
> installed at the system level. We suggested this a little while ago,
> but
> this was rejected by the nova team who valued the benefit of having a
> restricted test run so that we know we've got all of the depends
> properly specified.
> 
> To that end, after chatting with Brian Waldon, I put this up as a
> possible next try:
> 
> https://review.openstack.org/#/c/8949/
> 
> Which adds an additional testing environment that has system software
> enabled and also installs additional "optional" things. With that
> environment, we should be able to run a jenkins gate that tests
> things
> with full libvirt, and also tests the mysql upgrade paths, without
> screwing our fine friends who run OSX.
> 
> Fundamentally though - we're at a point of trying to have our cake
> and
> eat it too. Either we want comprehensive testing of all of the unit
> tests, or we want to be careful about not making the test environment
> to
> hard for a developer to exactly mimic.
> 
> I'm obviously on the side of having us have gating tests that some
> devs
> might not be able to do on their laptops - such as  running the
> libvirt
> tests properly. We're working on cloud software - worst case scenario
> if
> there's an intractable problem, as dev can always spin up an ubuntu
> image somewhere.
> 
> > Obviously this was all made worse by the transient problems we've
> > had
> > with the tests suite infrastructure these past 2 days, but
> > regardless
> > it seems like we have a gap in our merge approval procedures here.
> > 
> > IMHO, either SmokeStack needs to be made compulsory, or Jenkins
> > needs
> > to ensure tests are run on suitable hosts like SmokeStack does, or
> > both.
> 
> The second is much more possible and as I've pointed out is in work -
> but I do think we should develop a clear sense that it's important to
> us
> that we run these things properly even if it means direct local
> developer reproducibility is impacted.
> 
> Thanks!
> Monty
> 
> _______________________________________________
> Mailing list: https://launchpad.net/~openstack
> Post to     : openstack at lists.launchpad.net
> Unsubscribe : https://launchpad.net/~openstack
> More help   : https://help.launchpad.net/ListHelp
>