Excerpts from Ben Nemec's message of 2018-04-30 16:16:35 -0500: > Resending from an address that is subscribed to the list. Apologies to > those of you who get this twice. > > On 04/30/2018 10:06 AM, Doug Hellmann wrote: > > It would be useful to have more input from PTLs on this issue, so I'm > > CCing all of them to get their attention. > > > > Excerpts from Doug Hellmann's message of 2018-04-25 16:54:46 -0400: > >> It's time to talk about the next steps in our migration from python > >> 2 to python 3. > >> > >> Up to this point we have mostly focused on reaching a state where > >> we support both versions of the language. We are not quite there > >> with all projects, as you can see by reviewing the test coverage > >> status information at > >> https://wiki.openstack.org/wiki/Python3#Python_3_Status_of_OpenStack_projects > >> > >> Still, we need to press on to the next phase of the migration, which > >> I have been calling "Python 3 first". This is where we use python > >> 3 as the default, for everything, and set up the exceptions we need > >> for anything that still requires python 2. > >> > >> To reach that stage, we need to: > >> > >> 1. Change the documentation and release notes jobs to use python 3. > >> (The Oslo team recently completed this, and found that we did > >> need to make a few small code changes to get them to work.) > >> 2. Change (or duplicate) all functional test jobs to run under > >> python 3. > >> 3. Change the packaging jobs to use python 3. > >> 4. Update devstack to use 3 by default and require setting a flag to > >> use 2. (This may trigger other job changes.) > >> > >> At that point, all of our deliverables will be produced using python > >> 3, and we can be relatively confident that if we no longer had > >> access to python 2 we could still continue operating. We could also > >> start updating deployment tools to use either python 3 or 2, so > >> that users could actually deploy using the python 3 versions of > >> services. > >> > >> Somewhere in that time frame our third-party CI systems will need > >> to ensure they have python 3 support as well. > >> > >> After the "Python 3 first" phase is completed we should release > >> one series using the packages built with python 3. Perhaps Stein? > >> Or is that too ambitious? > >> > >> Next, we will be ready to address the prerequisites for "Python 3 > >> only," which will allow us to drop Python 2 support. > >> > >> We need to wait to drop python 2 support as a community, rather > >> than going one project at a time, to avoid doubling the work of > >> downstream consumers such as distros and independent deployers. We > >> don't want them to have to package all (or even a large number) of > >> the dependencies of OpenStack twice because they have to install > >> some services running under python 2 and others under 3. Ideally > >> they would be able to upgrade all of the services on a node together > >> as part of their transition to the new version, without ending up > >> with a python 2 version of a dependency along side a python 3 version > >> of the same package. > >> > >> The remaining items could be fixed earlier, but this is the point > >> at which they would block us: > >> > >> 1. Fix oslo.service functional tests -- the Oslo team needs help > >> maintaining this library. Alternatively, we could move all > >> services to use cotyledon (https://pypi.org/project/cotyledon/). > > For everyone's awareness, we discussed this in the Oslo meeting today > and our first step is to see how many, if any, services are actually > relying on the oslo.service functionality that doesn't work in Python 3 > today. From there we will come up with a plan for how to move forward. > > https://bugs.launchpad.net/manila/+bug/1482633 is the original bug. > > >> > >> 2. Finish the unit test and functional test ports so that all of > >> our tests can run under python 3 (this implies that the services > >> all run under python 3, so there is no more porting to do). > > And integration tests? I know for the initial python 3 goal we said > just unit and functional, but it seems to me that we can't claim full > python 3 compatibility until we can run our tempest jobs against python > 3-based OpenStack.
Good point. The wiki page lists the integrated-gate-py35 job for many projects, but not all will use that particular test job. I'm not sure what other sort of integration jobs we do have, but I agree we should have versions of them working for python 3. > > >> > >> Finally, after we have *all* tests running on python 3, we can > >> safely drop python 2. > >> > >> We have previously discussed the end of the T cycle as the point > >> at which we would have all of those tests running, and if that holds > >> true we could reasonably drop python 2 during the beginning of the > >> U cycle, in late 2019 and before the 2020 cut-off point when upstream > >> python 2 support will be dropped. > >> > >> I need some info from the deployment tool teams to understand whether > >> they would be ready to take the plunge during T or U and start > >> deploying only the python 3 version. Are there other upgrade issues > >> that need to be addressed to support moving from 2 to 3? Something > >> that might be part of the platform(s), rather than OpenStack itself? > > Alex can probably expand on this, but I know TripleO has some challenges > in this area. Specifically the fact that CentOS 7 will only ever > support Python 2 and CentOS 8 is planned to only support Python 3. Since > CentOS 8 is not a thing yet and no release dates are announced they're > having to use Fedora for Python 3 testing, which isn't something that > will be supported long-term. That makes things...complicated. > > Some more details are in the PTG discussion wrap-up thread: > http://lists.openstack.org/pipermail/openstack-dev/2018-March/128481.html > > That said, I believe the plan is to be testing on Python 3 by T, so I > guess that's ultimately the answer to your question. Yes, that's more or less what I was looking for. Doug > > >> > >> What else have I missed in these phases? Other jobs? Other blocking > >> conditions? > >> > >> Doug > __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
