Add comments to manage-projects about project-config syncing

There were questions around project-config syncing and the way it is
done in manage-projects during our last project renaming. I've since
read through teh code to try and understand things better and have added
comments to manage-projects.yaml indicating the risks here and why we
approach it the way we do. There is no functional change only an attempt
at better understanding for the future.

Change-Id: I60aa58a36108edce3e00ecf2ac10be3dee7e8ea0
Clark Boylan 1 year ago
parent 2c1a449a42
commit 07c7f757d0

@ -1,3 +1,23 @@
# Note that we don't do a sync-project-config before gitea-git-repos
# because sync-project-config's primary purpose is to update
# /opt/project-config on the remote host. review.o.o needs this to be
# updated as jeepyb executes there against the local checkout.
# gitea-git-repos runs against the project-config on bridge which has
# already been synced from Zuul to bridge by Zuul.
# sync-project-config does update project-config from master rather than
# the Zuul state when run in a periodic or opendev-prod-hourly pipelines
# but this playbook is never run in those pipelines. It only runs in deploy
# in response to merged changes.
# This does mean that we need to be careful landing sequences of changes
# to rename projects as only the last one in the series should actually
# run this playbook. Historically, we've avoided problems because Zuul
# hasn't been able to run post merge jobs at all for intermediate changes
# after a rename. Only the last change has been in a consistent state
# which ends up running this playbook. This has mostly been done by chance
# rather than intentionally and we should take care going forward to not
# get this wrong.
- hosts: "gitea:!disabled"
name: "Create repos on gitea servers"