train: no module named swift.common.ring

[Corey Bryant]

This is likely due to the drop of swift py2 packages in train and needing to support py3 packages in the charms.

2019-08-23 13:04:08 DEBUG config-changed RuntimeError: Decoding the result from the call to manager.py resulted in error 'The call within manager.py failed with the error: 'No module named swift.common.ring'. The call was: path=['initialize_ring'], args=('/etc/swift/account.builder', 8, 3, 0), kwargs={}' (command: path=['initialize_ring'], args=('/etc/swift/account.builder', 8, 3, 0), kwargs={}

[Corey Bryant (corey.bryant)]

To recreate just deploy with train-proposed. Attached is the full traceback.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/680228
Committed: https://git.openstack.org/cgit/openstack/charm-swift-proxy/commit/?id=5f3735f884c33551bbe6fabf4dc71861c126e23d
Submitter: Zuul
Branch: master

commit 5f3735f884c33551bbe6fabf4dc71861c126e23d
Author: Corey Bryant <email address hidden>
Date: Wed Sep 4 14:49:39 2019 +0000

    py3: Switch packages to Python 3 for train and later

    Switch package install to Python 3 for OpenStack Train and later.

    When upgrading, remove any python-* packages that were explicitly
    installated and then autoremove --purge any dependencies that are
    no longer required.

    This patch also includes the following related changes:
      * Use the common files package, swift, rather than python-swift
        as the package name when determining releases.
      * Drop the python2 shebang from manager.py in favor of specifying
        the interpreter on the subprocess call. The python interpreter
        version must match the python version of the OpenStack payload
        due to the swift library imports.
      * Enable the cPickle import in manager.py for Python 3
        (C-optimized module name is _pickle), and fix 'result'
        variable that is a set type but should be a dict type.

    Change-Id: Ia3fdbf2020137bcf39039478ee3606717d3d6e20
    Closes-Bug: #1841184