[openstack-dev] [packaging] liberty doesn't have caps on deps

Robert Collins robertc at robertcollins.net
Thu Oct 15 22:12:22 UTC 2015

On 16 October 2015 at 08:10, Matthew Thode <prometheanfire at gentoo.org> wrote:
> On 10/15/2015 02:04 PM, Robert Collins wrote:
>>> Where are my caps?
>> The known good versions of dependencies for liberty are
>> http://git.openstack.org/cgit/openstack/requirements/tree/upper-constraints.txt?h=stable/liberty
> That's good, does that represent an upper constraint for the lower
> constraint imposed by by the package?  Why is this kept separate?
> Keeping it separate means that it's not trivial to merge them with
> what's in each package's requirements.

It represents *one* known good combination of packages. We know that
that combination passed CI, and we then do all our tests with it. To
change it, we run it past CI and only move onto using the new set when
its passed CI.

If we merged it to each packages requirements, we'd reintroduce the
deadlock that caused so much grief only 6 months back - I don't see
any reason, desire, or tolerance for doing that upstream.

Its kept separate because it requires 2N commits to shift known-good
caps around for N repos using per-repo rules.

With hundreds of repositories, it takes us hundreds of commits in two
batches - and a round trip time of 2 hours per batch (check + gate) to
shift *a single* requirement. With hundreds of dependencies, thats an
intolerable amount of overhead.

>> You should be able to trivially pull those versions out and into your
>> liberty set of packages.
>> Theres another iteration on this in discussion now, which has to do
>> with backwards compat *and testing of cap changes*, we'll be in the
>> backwards compat fishbowl session in Tokyo if you're interested.
>> -Rob
> I'll be at the fishbowl :D



Robert Collins <rbtcollins at hp.com>
Distinguished Technologist
HP Converged Cloud

More information about the OpenStack-dev mailing list