Open Stack

Hi All,

I discussion recently came up inside of nova about what it means
supported version for a dependency means.  in libvirt we gate on the
minimal version that we support but for all python dependencies we
gate on the highest version that passes our requirements. While we all
agree that having two different ways of choosing which version to test
(min and max) is bad, there are good arguments for doing both.

testing most recent version:
    * We want to make sure we support the latest and greatest
    * Bug fixes
    * Quickly discover backwards incompatible changes so we can deal
with them as they arise instead of in batch

Testing lowest version supported:
    * Make sure we don't land any code that breaks compatibility with
the lowest version we say we support


A few questions and ideas on how to move forward.
    * How do other projects deal with this? This problem isn't unique
in OpenStack.
    * What are the issues with making one gate job use the latest
versions and one use the lowest supported versions?
    * Only test some things on every commit or every day (periodic
jobs)? But no one ever fixes those things when they break? who wants
to own them? distros? deployers?
    * Other solutions?
    * Does it make sense to gate on the lowest version of libvirt but
the highest version of python libs?
    * Given our finite resources what gets us the furthest?


best,
Joe Gordon
John Garbutt