Open Stack

Hi,

I'd like to draw your attention to some things that we're changing in
Zuul v3 that affect stable branches.

We found a couple of interrelated issues where Zuul's behavior did not
match our expectations, and we also had some incorrect advice in the
migration doc.

We're rolling out a new version of Zuul that corrects the issues, and
the migration doc has been updated.  The main things to know are:

* If your project has stable branches, we recommend backporting the Zuul
  config along with all the playbooks and roles that are in your repo to
  the stable branches.

That's because:

* Generally speaking, jobs defined in a branch of your project should
  only apply to changes to that branch.  So the copy of a job defined in
  'master' should be used for changes to 'master'.  And the copy defined
  in 'stable/pike' should be used for changes to 'stable/pike'.

* Backporting this now is a bit of extra work that needs to happen as
  part of this initial transition.  But going forward, the workflow will
  be *much* simpler.  The next stable branch will begin its life with
  all the content from master already in place, and the two branches can
  simply naturally diverge as you would expect.

The Zuul v3 migration docs have been updated to reflect this:

  https://docs.openstack.org/infra/manual/zuulv3.html#stable-branches

If something about the new arrangement isn't working out for you, there
are other options.  Let us know and we can work through them.

-Jim