Track db migrations in version control

[thatarchguy]

I didn't quite understand the flask-migrate process.

It becomes really useful when doing upgrade of the software that requires a database migration.

Instead of having the user generate their own migrations with python manage.py db migrate && python manage.py db upgrade, we can have finer control between versions and such if we track the migrations in git.

They simply do a python manage.py db upgrade and it will apply each migration in order.

[mprahl]

As I understand it, this won't work because the user won't have the table in their database that keeps track of the state of migrations. Maybe there is a way around it though.

[thatarchguy]

hm.. that makes this very difficult to do properly. I know django handles this pretty seamlessly.

[thatarchguy]

If they have the migrations/ folder and the database created (just create database servermail), then the user can simply run python manage.py db upgrade and it works fine.

If the user already has it built and needs to upgrade to latest version, they simply run python manage.py db update

The problem is that the python manage.py createdb command uses the folder db/migrations instead of migrations. Is there a reason for it to go into the db/migrations folder? We can override the default with --directory db/migrations with the current layout. But that seems unnecessary unless I am mistaken?

[mprahl]

@thatarchguy, so the reason why we stored the migrations in the db folder was to allow us to mount the /opt/postmaster/git/db folder in Docker. We couldn't mount /opt/postmaster/git/migrations because the migration would fail because a folder already existed.