On 6/2/20 6:34 AM, Neil Jerram wrote:
> Does anyone know the most recent OpenStack version that
> _can't_ easily be run with Python 3?  I think the full answer to this
> may have to consider distro packaging, as well as the underlying code
> support.
>
> For example, I was just looking at switching an existing Queens setup,
> on Ubuntu Bionic, and it can't practically be done because all of the
> scripts - e.g. /usr/bin/nova-compute - have a hashbang line that says
> "python2".
>
> So IIUC Queens is a no for Python 3, at least in the Ubuntu packaging.
>
> Do you know if this is equally true for later versions than Queens? 
> Or alternatively, if something systematic was done to address this
> problem in later releases?  E.g. is there a global USE_PYTHON3 switch
> somewhere, or was the packaging for later releases changed to hardcode
> "python3" instead of "python2"?  If so, when did that happen?
>
Stein was the release where we had a cycle goal to get everyone using
Python 3:

https://governance.openstack.org/tc/goals/selected/stein/python3-first.html

Part of the completion criteria for that goal was that all projects
should, at a minimum, be running py3.6 unit tests. So a couple of
caveats there - unit tests don't always identify issues that you can run
in to actually running full functionality, and not every project was
able to complete the cycle goal completely. Most did though.

So I think Stein likely should work for you, but of course Train or
Ussuri will have had more time to identify any missed issues and the like.

I hope this helps.

Sean