Update instructions for database migration with additional steps that may be needed

[Henry Gessau]

These instructions

https://wiki.openstack.org/wiki/Neutron/DatabaseMigration

(and the README referred to therein) do not mention that backend-specific methods will be generated in the migration script, and that the developer must replace them with sa.* abstract methods.

[Sean M. Collins (scollins)]

Does anyone use the automatic migration? I found it more difficult to use than just writing a migration script from scratch - since you have to go through and replace everything with sa.* methods - it may end up costing more time than it saves?

[Armando Migliaccio (armando-migliaccio)]

We no longer keep this info in the wiki.

[Armando Migliaccio (armando-migliaccio)]

https://github.com/openstack/neutron/blob/master/doc/source/devref/alembic_migrations.rst

[Armando Migliaccio (armando-migliaccio)]

@Henry: can you check if this is still relevant?

[Henry Gessau (gessau)]

I will close it with a doc update soon.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/242868

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/242868
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=468de2d767b6cc984fa4fc3b150721368f889a77
Submitter: Jenkins
Branch: master

commit 468de2d767b6cc984fa4fc3b150721368f889a77
Author: Henry Gessau <email address hidden>
Date: Thu Nov 5 11:47:13 2015 -0500

    More instructions for neutron-db-manage revision --autogenerate

    More detailed instructions for --autogenerate, including how to rely
    less on devstack. Also some tweaks to scripts and requirements to
    simplify the process.

    Closes-Bug: #1197570

    Change-Id: I97043b30a8df7408a73af38c6a015fc0dcf82571

[Thierry Carrez (ttx)]

This issue was fixed in the openstack/neutron 8.0.0.0b1 development milestone.