Open Stack

I'm wondering if someone on the infra team can give me some pointers on how to
approach something, and looking for any general feedback as well.

Background
==========
We've had things like the DocImpact tag that could be added to commit messages
that would tie into some automation to create a launchpad bug when that commit
merged. While we had a larger docs team and out-of-tree docs, I think this
really helped us make sure we didn't lose track of needed documentation
updates.

I was able to find part of how that is implemented in jeepyb:

http://git.openstack.org/cgit/openstack-infra/jeepyb/tree/jeepyb/cmd/notify_impact.py

Current Challenge
=================
Similar to the need to follow up with documentation, I've seen a lot of cases
where projects have added features or made other changes that impact downstream
consumers of that project. Most often, I've seen cases where something like
python-cinderclient adds some functionality, but it is on projects like Horizon
or python-openstackclient to proactively go out and discover those changes.

Not only just seeking out those changes, but also evaluating whether a given
change should have any impact on their project. So we've ended up in a lot of
cases where either new functionality isn't made available through these
interfaces until a cycle or two later, or probably worse, cases where something
is now broken with no one aware of it until an actual end user hits a problem
and files a bug.

ClientImpact Plan
=================
I've run this by a few people and it seems to have some support. Or course I'm
open to any other suggestions.

What I would like to do is add a ClientImpact tag handling that could be added
very similarly to DocImpact. The way I see it working is it would work in much
the same way where project's can use this to add the tag to a commit message
when they know it is something that will require additional work in OSC or
Horizon (or others). Then when that commit merges, automation would create a
launchpad bug and/or Storyboard story, including a default set of client
projects. Perhaps we can find some way to make those impacted clients
configurable by source project, but that could be a follow-on optimization.

I am concerned that this could create some extra overhead for these projects.
But my hope is it would be a quick evaluation by a bug triager in those
projects where they can, hopefully, quickly determine if a change does not in
fact impact them and just close the ones they don't think require any follow on
work.

I do hope that this will save some time and speed things up overall for these
projects to be notified that there is something that needs their attention
without needing someone to take the time to actively go out and discover that.

Help Needed
===========
>From the bits I've found for the DocImpact handling, it looks like it should
not be too much effort to implement the logic to handle a ClientImpact flag.
But I have not been able to find all the moving parts that work together to
perform that automation.

If anyone has any background knowledge on how DocImpact is implemented and can
give me a few pointers, I think I should be able to take it from there to get
this implemented. Or if there is someone that knows this well and is interested
in working on some of the implementation, that would be very welcome too!

Sean