[rocky] ImportError: No module named versions

[Frode Nordahl]

# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.1 LTS
Release: 18.04
Codename: bionic

# dpkg -l | grep neutron
ii neutron-common 2:13.0.0~b2-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - common
ii neutron-plugin-ml2 2:13.0.0~b2-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - ML2 plugin
ii neutron-server 2:13.0.0~b2-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - server
ii python-neutron 2:13.0.0~b2-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - Python library
ii python-neutron-dynamic-routing 2:13.0.0~b2-0ubuntu1~cloud0 all OpenStack Neutron Dynamic Routing - Python 2.7 library
ii python-neutron-fwaas 1:13.0.0~b2-0ubuntu1~cloud0 all Firewall-as-a-Service driver for OpenStack Neutron
ii python-neutron-lbaas 2:13.0.0~b2-0ubuntu1~cloud0 all Loadbalancer-as-a-Service driver for OpenStack Neutron
ii python-neutron-lib 1.15.0-0ubuntu1~cloud0 all Neutron shared routines and utilities - Python 2.7
ii python-neutronclient 1:6.7.0-0ubuntu1 all client API library for Neutron - Python 2.7

While attempting to deploy OpenStack Rocky version of Neutron I get this traceback in the logs for neutron-server:
2018-07-30 15:15:51.112 8942 CRITICAL neutron [req-ecf2714d-2c18-4ed3-afff-49dac1ac9dbe - - - - -] Unhandled error: ImportError: No module named versions
2018-07-30 15:15:51.112 8942 ERROR neutron Traceback (most recent call last):
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/bin/neutron-server", line 10, in <module>
2018-07-30 15:15:51.112 8942 ERROR neutron sys.exit(main())
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/cmd/eventlet/server/__init__.py", line 19, in main
2018-07-30 15:15:51.112 8942 ERROR neutron server.boot_server(wsgi_eventlet.eventlet_wsgi_server)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/server/__init__.py", line 42, in boot_server
2018-07-30 15:15:51.112 8942 ERROR neutron server_func()
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/server/wsgi_eventlet.py", line 24, in eventlet_wsgi_server
2018-07-30 15:15:51.112 8942 ERROR neutron neutron_api = service.serve_wsgi(service.NeutronApiService)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/service.py", line 89, in serve_wsgi
2018-07-30 15:15:51.112 8942 ERROR neutron LOG.exception('Unrecoverable error: please check log '
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
2018-07-30 15:15:51.112 8942 ERROR neutron self.force_reraise()
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
2018-07-30 15:15:51.112 8942 ERROR neutron six.reraise(self.type_, self.value, self.tb)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/service.py", line 86, in serve_wsgi
2018-07-30 15:15:51.112 8942 ERROR neutron service.start()
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/service.py", line 62, in start
2018-07-30 15:15:51.112 8942 ERROR neutron self.wsgi_app = _run_wsgi(self.app_name)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/service.py", line 290, in _run_wsgi
2018-07-30 15:15:51.112 8942 ERROR neutron app = config.load_paste_app(app_name)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/common/config.py", line 122, in load_paste_app
2018-07-30 15:15:51.112 8942 ERROR neutron app = loader.load_app(app_name)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/oslo_service/wsgi.py", line 353, in load_app
2018-07-30 15:15:51.112 8942 ERROR neutron return deploy.loadapp("config:%s" % self.config_path, name=name)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 247, in loadapp
2018-07-30 15:15:51.112 8942 ERROR neutron return loadobj(APP, uri, name=name, **kw)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 272, in loadobj
2018-07-30 15:15:51.112 8942 ERROR neutron return context.create()
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 710, in create
2018-07-30 15:15:51.112 8942 ERROR neutron return self.object_type.invoke(self)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 144, in invoke
2018-07-30 15:15:51.112 8942 ERROR neutron **context.local_conf)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/util.py", line 55, in fix_call
2018-07-30 15:15:51.112 8942 ERROR neutron val = callable(*args, **kw)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/urlmap.py", line 31, in urlmap_factory
2018-07-30 15:15:51.112 8942 ERROR neutron app = loader.get_app(app_name, global_conf=global_conf)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 350, in get_app
2018-07-30 15:15:51.112 8942 ERROR neutron name=name, global_conf=global_conf).create()
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 710, in create
2018-07-30 15:15:51.112 8942 ERROR neutron return self.object_type.invoke(self)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 144, in invoke
2018-07-30 15:15:51.112 8942 ERROR neutron **context.local_conf)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/util.py", line 55, in fix_call
2018-07-30 15:15:51.112 8942 ERROR neutron val = callable(*args, **kw)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/neutron/auth.py", line 47, in pipeline_factory
2018-07-30 15:15:51.112 8942 ERROR neutron app = loader.get_app(pipeline[-1])
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 350, in get_app
2018-07-30 15:15:51.112 8942 ERROR neutron name=name, global_conf=global_conf).create()
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 362, in app_context
2018-07-30 15:15:51.112 8942 ERROR neutron APP, name=name, global_conf=global_conf)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 458, in get_context
2018-07-30 15:15:51.112 8942 ERROR neutron section)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 517, in _context_from_explicit
2018-07-30 15:15:51.112 8942 ERROR neutron value = import_string(found_expr)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 22, in import_string
2018-07-30 15:15:51.112 8942 ERROR neutron return pkg_resources.EntryPoint.parse("x=" + s).load(False)
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2324, in load
2018-07-30 15:15:51.112 8942 ERROR neutron return self.resolve()
2018-07-30 15:15:51.112 8942 ERROR neutron File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 2330, in resolve
2018-07-30 15:15:51.112 8942 ERROR neutron module = __import__(self.module_name, fromlist=['__name__'], level=0)
2018-07-30 15:15:51.112 8942 ERROR neutron ImportError: No module named versions
2018-07-30 15:15:51.112 8942 ERROR neutron

[Frode Nordahl (fnordahl)]

As coreycb pointed out this seems to be a issue of out of date api-paste.ini:
https://github.com/openstack/neutron/blob/master/releasenotes/notes/noneutronversions-fbbdb98f350767d8.yaml

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/587282
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-api/commit/?id=bc8a91dea05b62b8ce0c9e83f539a0f321b9b1b4
Submitter: Zuul
Branch: master

commit bc8a91dea05b62b8ce0c9e83f539a0f321b9b1b4
Author: Frode Nordahl <email address hidden>
Date: Tue Jul 31 06:43:11 2018 +0200

    Update `api-paste.ini` for Rocky

    Removal of entrypoint `neutron.api.versions:Versions.factory`
    mandates a new version of the `api-paste.ini` file for Rocky.

    Reference:
    https://github.com/openstack/neutron/blob/master/releasenotes/notes/noneutronversions-fbbdb98f350767d8.yaml

    Change-Id: I0405c698190c84b521e52ba02e6fb1c5396be9be
    Closes-Bug: #1784405