jenkins tests fails for neutron/grizzly duo to iso8601 version requirement conflict

Fix proposed to branch: master
Review: https://review.openstack.org/58687

Marking invalid on infrastructure since this is something which has to be fixed within the affected projects.

I don't think this can be fixed in Glance stable/grizzly or any client,
issue is that Tempest is installing clients from trunk into the same venv as stable/grizzly services being tested!

It should be either separate venv for clients or we must introduce stable/* from clients.
Related openstack-dev thread is http://lists.openstack.org/pipermail/openstack-dev/2013-November/020587.html

Can we just revert the requirements changes which bring in newer is08601 for now, until this can be done in a safer manner? This is currently blocking release of critical security fixes.

Bumping requirement on stable/* doesn't look like a right approach, wasn't there a design session about freezing requirements on stable/* ?

Also iso8601>=0.1.8 didn't work on Grizzly when I tried it: https://review.openstack.org/53703
and then went with <=0.1.4 instead: https://review.openstack.org/55998

> Also iso8601>=0.1.8 didn't work on Grizzly when I tried it:

Here was another attempt with some tests adjusted before I gave up: https://review.openstack.org/55939
I can restore it, if anyone would like to fix tests completely.

The upshot of that summit session was that there was a fair amount of support for the idea of capping dependencies we don't produce in the requirements files on stable branches of projects participating in our integrated release, but that we should seek further consensus prior to doing so. This bug, on the other hand, is about a dependency we *do* produce but which does not itself participate in the integrated release, and the intent there was that we should introduce additional backward compatibility testing in the gate to insure against client projects introducing changes (including transitive dependencies) which are incompatible with stable release branches of projects interacting with or consuming them. Basically once a client project merged a change to require a newer iso8601 than was allowed in one or more stable server branches, integration gating was instantly broken for that stable release.

It was suggested in bug 1242501 as well as other places (notably during discussions with Mark W. and other Glance devs on #openstack-infra shortly prior to the summit) that they should pursue support for both iso8601 0.1.4 and 0.1.8, but this was rejected at the time because it meant either exhibiting inconsistent behavior depending on which was installed or reimplementing a significant amount of iso8601 0.1.8 in Glance. If the proposed backward-compat testing were in place, the only options to get newer is08601 support through the gate would have been for Glance to support both, or for the stable branches of projects to be fixed such that they would also work with newer iso8601.

This is causing the tempest-dsvm-neutron job fail for all the proposed grizzly patches, preventing any patch for grizzly from being checked or verified.

Would it be possible to use an older version of iso8601 for grizzly branches?

Unfortunately not. The problem here is newer OpenStack libraries prematurely abandoning support for older iso8601 when Grizzly (which imports these libraries for intercommunication) does not work with it. Also this makes it tough to test new clients against Grizzly servers on the same machine, since their declared iso8601 requirements conflict with one another. Testing Grizzly with older iso8601 at the moment would mean testing it against older (no longer security-supported) OpenStack client libraries. The options I see here are:

A. Revert work requiring newer iso8601 until after Grizzly is no longer supported.

B. Adjust current libraries to support both old and new iso8601.

C. Modify Grizzly to support new iso8601.

So let's try C. although I don't think bumping required versions of dependencies on stable is a good idea in general, but we need to unblock stable/grizzly somehow.

I've restored https://review.openstack.org/55939 and tests pass now, but I'm not sure if that's enough to declare grizzly Glance is fully working with iso8601 - I'll add more Glance floks as reviewers.