add --package flag to alembic init to support building as package

[sqlalchemy-bot]

Migrated issue, originally created by Luke Schlather (lukeschlather)

When I run alembic init, it generates alembic.ini, alembic, and alembic/versions/ .

I run this in a namespaced directory (e.g. database) under a python package. It would be nice if alembic automatically detected that it was being created within a python package, and modified the Manifest, and/or added init.py files to ensure it is distributed along with the package.

As an example, suppose I had a structure like:

#!

* mypackage
** setup.py
*** database 

If I were to run "alembic init" in the database directory, it would be nice if alembic init detected the setup.py in the root of the project, created a MANIFEST.in if need be, and created init.py files so it instead looks like:

#!

* mypackage
** setup.py
** MANIFEST.in
*** database 
**** alembic/__init__.py
**** alembic/versions/__init__.py

[sqlalchemy-bot]

Michael Bayer (zzzeek) wrote:

I'd be more comfortable with a flag --update-manifest. Way way less risky and surprising. what do you think?

[sqlalchemy-bot]

Luke Schlather (lukeschlather) wrote:

Everyone I work with (including me) is continually surprised when they deploy a new package and alembic fails. I think --update-manifest is a decent place to put the feature, but I know my company's documentation is going to say to always use the option.

I do get the worry, since our packaging setup certainly isn't universal and I'm sure there are cases where updating the manifest could have unexpected results. Also the logic around update-or-create MANIFEST.in could be a little surprising, though simply appending if exists is probably fine.

[sqlalchemy-bot]

Michael Bayer (zzzeek) wrote:

Um...why aren't you using a wildcard in your MANIFEST.in? there's no need to add individual __init__.py files, and also alembic init doesn't create any __init__.py files anyway. were you looking for individual line items for every new version file?

[sqlalchemy-bot]

Michael Bayer (zzzeek) wrote:

oh I see you want it to create __init__.py files. These need to all be options, preferably one that uses a package name for "script_location" in alembic.ini.

[sqlalchemy-bot]

Michael Bayer (zzzeek) wrote:

like this:

alembic init --package myapp.foo  

it will then use PYTHONPATH and import to figure out where "myapp.foo" is supposed to be and will generate the entrypoint in alembic.ini script_location, and make sure whatever __init__.py is necessary.

[sqlalchemy-bot]

Luke Schlather (lukeschlather) wrote:

alembic init --package myapp.foo

Sounds good. In that case it seems more reasonable to me to make --update-manifest assumed, since it shouldn't have to do as much guessing.

[sqlalchemy-bot]

Changes by Michael Bayer (zzzeek):

• edited description

[sqlalchemy-bot]

Changes by Michael Bayer (zzzeek):

• changed title from "alembic init should ensure it is packaged properly" to "add --package flag to alembic init to support buil"