[rdo-list] Third party DLRN CI and the need for a "-head" builder

[David Moreau Simard]

Hi,

So with the help of Paul Belanger, we've identified the issue that
prevented the "openstack-check-verified" pipeline from working.

The Zuul openstack-check-verified pipeline [1] from
review.rdoproject.org can be used to trigger builds on upstream
projects on each patchset, only when Jenkins has +1'd it.
The goal with this pipeline is to do third party CI with DLRN in order
to try and build projects' patches to warn us for failure to build
errors ahead of time, even before the change merges.

We're not planning on voting on the Gerrit changes, it's solely to
check if there are any issues building the project with that
particular patch.

So we really have two Ocata DLRN instances now, one that is pinned to
upper-constraints [2] and one that builds the "master of everything"
[3].
I was thinking... If we're able to do third party CI against upstream
with DLRN do we need that "head" instance ?

The "head" instance exists, as far as I know, to let us know if
anything from unpinned projects fails to build.
The third party CI will let us know that -- and even before, ahead of
time, before the change causing the failure even merges.

Thoughts ?

[1]: https://review.rdoproject.org/r/gitweb?p=config.git;a=blob;f=zuul/upstream.yaml;h=f4cad72201cf602a06d16ec2d84c23d0dadbae18;hb=HEAD#l22
[2]: https://trunk.rdoproject.org/centos7-master/
[3]: https://trunk.rdoproject.org/centos7-master-head/

David Moreau Simard
Senior Software Engineer | Openstack RDO

dmsimard = [irc, github, twitter]