make stable branches in openstack/requirements

[James E. Blair]

Base the global requirements on an aggregate intersection of all integrated release projects for each stable branch, cap them <= the latest versions matching those ranges to eliminate future surprises, and then sync those projects to it. Also include all indirect/transitive dependencies to prevent external dependency changes from influencing testability of these projects.

[James E. Blair (corvus)]

The branches have been created.

[Jeremy Stanley (fungi)]

Related review (to allow the mirror script to take a specific branch name on the command line):

https://review.openstack.org/28346

The impetus is, since the openstack/requirements project now has stable branches, the mirror script is taking three times as long to run. Changes to the repo are only going to land on a specific branch however, so long-term we won't want to update mirrors for all branches when triggered from a job in the post queue (only when triggered from a periodic job).

Once that merges, we can add the ability to create branch subdirectories of the current mirror. I'll ponder the layout a bit and throw some ideas in here.

[Jeremy Stanley (fungi)]

So think the first phase here should be to create a parallel tree for branch-specific mirrors and prepopulate them with the contents of the current openstack pypi mirror, which can remain the master branch mirror or get moved and symlinked to be adjacent to the others. In the interim, using rewrite rules in the apache vhost config should make it possible to transition these without stomping on the current namespace.

[Jeremy Stanley (fungi)]

This is actually just going to be stable/grizzly and later (I'm simply going to hard pin everything in stable/folsom including transitive dependencies for the duration of its remaining support).

I'm working on backporting the current state of openstack/requirements to the stable/grizzly branch so we can leverage the havana improvements there.

[Jeremy Stanley (fungi)]

Updated the description to reflect current direction of this work. We'll apply this to folsom and grizzly for expediency, but discuss whether for havana and later we could begin to apply the requirements enforcement solutions we've developed during the course of the most recent release cycle.

[Jeremy Stanley (fungi)]

Folsom support ended, grizzly is still too broken in gating at the moment to get the backports from havana/master merged to openstack/requirements. The Havana jobs should be realtively easy to tackle at this point since the machinery is mostly the same as what's in master now.

[Jeremy Stanley (fungi)]

Sit by the river and the corpses of your enemies will float by. Havana's been working for a while and Grizzly is past due for removal (EOL was scheduled last Thursday).