Open Stack

Hi,

We need to merge a backwards incompatible change to Zuul master.

The change is: https://review.openstack.org/482856 and it makes Gerrit
label entries case sensitive.  Unfortunately, some combinations of
Gerrit versions and underlying database configurations make this both
necessary and difficult to handle seamlessly.

This will affect both installations continuously delivered from git
master, as well as those that are upgraded to the latest releases.

The complexity of this situation leaves us few options other than to
make this change and minimize the impact by isolating it and providing
an upgrade plan.

The upgrade plan is the same regardless of whether you run Zuul
continuously deployed from master or releases.

Upgrade Procedure
-----------------

The latest release of Zuul, as of this writing, is 2.5.2.  It treats all
Gerrit labels as case insensitive, however, if a label is capitalized in
Zuul's layout configuration with this version, typical gate pipelines
may not function correctly.  Therefore:

1) Prepare, *but do not merge*, a patch to change the case of all Gerrit
labels in layout.yaml.  Typically, this would mean changing instances of
"verified:" to "Verified:" or "workflow:" to "Workflow:".

2) Next Tuesday, September 26, we will merge
https://review.openstack.org/482856 and release version 2.6.0, which
switches to the case-sensitive behavior (and contains no other
substantive changes).  Once this change is merged to the master branch
and and the new version of Zuul is released is released, prepare to
upgrade.

3) Merge the change prepared in step 1, then upgrade to 2.6.0 (or the
master branch tip) immediately afterword and restart Zuul.

Thanks,

Jim