heroku-buildpack-python/Readme.md

virtualenv

pip

Django settings.py

Sets up a db for every ENV ${NAME}_URL => postgres:// var:

DATABASES["DATABASE"]
DATABASES["SHARED_DATABASE"]
DATABASES["HEROKU_POSTGRESQL_ONYX"]

Aliases DATABASE_URL to default database:

DATABASES["default"] = DATABASES["DATABASE"]

Injected right after DATABASES = {...}

Hooks

Uses a Makefile for user-controlled hooks into slug compilation. Target environment will be evald in the build script, allowing custom exports. PIP_OPTS is passed to pip if set.

environment:
	export PIP_OPTS=--upgrade