DB migration broken

It broke kolla-ansible gates as well. :/

Thought we get this on VPNaaS:

"+++ neutron-db-manage --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugins/ml2/ml2_conf.ini --subproject neutron-vpnaas upgrade head",
    "INFO [alembic.runtime.migration] Context impl MySQLImpl.",
    "INFO [alembic.runtime.migration] Will assume non-transactional DDL.",
    "/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py:152: UserWarning: Revision 24f28869838b referenced from 24f28869838b -> 41b509d10b5e (head), VPNaaS endpoint groups is not present",
    " util.warn(",
    "Traceback (most recent call last):",
    " File \"/var/lib/kolla/venv/bin/neutron-db-manage\", line 8, in <module>",
    " sys.exit(main())",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 635, in main",
    " return_val |= bool(CONF.command.func(config, CONF.command.name))",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 179, in do_upgrade",
    " run_sanity_checks(config, revision)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 619, in run_sanity_checks",
    " script_dir.run_env()",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/base.py\", line 489, in run_env",
    " util.load_python_file(self.dir, \"env.py\")",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/util/pyfiles.py\", line 98, in load_python_file",
    " module = load_module_py(module_id, path)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/util/compat.py\", line 184, in load_module_py",
    " spec.loader.exec_module(module)",
    " File \"<frozen importlib._bootstrap_external>\", line 783, in exec_module",
    " File \"<frozen importlib._bootstrap>\", line 219, in _call_with_frames_removed",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron_vpnaas/db/migration/alembic_migrations/env.py\", line 88, in <module>",
    " run_migrations_online()",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron_vpnaas/db/migration/alembic_migrations/env.py\", line 79, in run_migrations_online",
    " context.run_migrations()",
    " File \"<string>\", line 8, in run_migrations",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/runtime/environment.py\", line 846, in run_migrations",
    " self.get_context().run_migrations(**kw)",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/runtime/migration.py\", line 509, in run_migrations",
    " for step in self._migrations_fn(heads, self):",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/neutron/db/migration/cli.py\", line 609, in check_sanity",
    " for script in script_dir.revision_map.iterate_revisions(",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py\", line 777, in _iterate_revisions",
    " uppers = util.dedupe_tuple(self.get_revisions(upper))",
    " File \"/var/lib/kolla/venv/lib/python3.8/site-packages/alembic/script/revision.py\", line 321, in get_revisions",
    " resolved_id,...

By the exception in https://storage.gra.cloud.ovh.net/v1/AUTH_dcaab5e32b234d56b626f72581e3644c/zuul_opendev_logs_141/749060/3/check/neutron-tempest-plugin-bgpvpn-bagpipe/141ddec/job-output.txt , it seems that bgpvpn and bagpipe liberty alembic branch must be squashed to Pike, but not sure about if that is really the only solution.

Fix proposed to branch: master
Review: https://review.opendev.org/749696

For bagpipe the patch from Rodolfo: https://review.opendev.org/749687

How's it going?

@Radosław: It should be fixed with revert https://review.opendev.org/#/c/749866/

Actually https://review.opendev.org/#/c/749866/ just avoids failures but I will keep this bug open as to fix it properly we will need to squash db migrations in that stadium project also and we can use this bug to track that.

Ok, thanks @Sławek for confirming. It means we (kolla) can restore these optional migrations.

Change abandoned by Rodolfo Alonso Hernandez (<email address hidden>) on branch: master
Review: https://review.opendev.org/749696
Reason: We have too many external dependencies. [1] is not going to happen.

[1]https://review.opendev.org/#/c/741676/