Open Stack

On Fri, May 15, 2015, Mike Bayer <mbayer at redhat.com> wrote:
> 
> 
> On 5/15/15 9:31 AM, Doug Hellmann wrote:
>> This seems more complicated than needed. If we just stop writing the
>> sqlalchemy-migrate scripts and don't change them, then for 1 cycle we
>> have to run both sets of migrations and after that we can just run
>> alembic.
> Then we have a forever-in-perpetuity dependency on SQLAlchemy-Migrate 
> which must be maintained forever for to maintain compatibility with all 
> new SQLAlchemy, oslo.db, etc. releases, despite it never being used for 
> anythine new, because it will be impossible to install an Openstack 
> application without running through the first set of migrate scripts first.
> 
> The SQLAlchemy-Migrate dependency must be dropped and the project has to 
> be EOL'ed at some point.   Leaving it in is definitely the more 
> complicated alternative.

Neutron has used alembic since its birth (Folsom release), but during the Juno
cycle we consolidated all the Folsom to Havana migrations into one
"havana_initial" migration. That is now the start migration for Neutron.

Nova should be able to do something similar in a cycle or two: setting
liberty_initial as the start migration with no legacy before it.