Heroku django new database settings

Heroku just announced that injection of database settings, meaning:

heroku run cat your_project/settings.py

Outputs something like this
import os
import sys
import urlparse

# Register database schemes in URLs.
urlparse.uses_netloc.append('postgres')
urlparse.uses_netloc.append('mysql')

try:

    # Check to make sure DATABASES is set in settings.py file.
    # If not default to {}

    if 'DATABASES' not in locals():
        DATABASES = {}

    if 'DATABASE_URL' in os.environ:
        url = urlparse.urlparse(os.environ['DATABASE_URL'])

        # Ensure default database exists.
        DATABASES['default'] = DATABASES.get('default', {})

        # Update with environment configuration.
        DATABASES['default'].update({
            'NAME': url.path[1:],
            'USER': url.username,
            'PASSWORD': url.password,
            'HOST': url.hostname,
            'PORT': url.port,
        })
        if url.scheme == 'postgres':
            DATABASES['default']['ENGINE'] = 'django.db.backends.postgresql_psycopg2'

        if url.scheme == 'mysql':
            DATABASES['default']['ENGINE'] = 'django.db.backends.mysql'
except Exception:
    print 'Unexpected error:', sys.exc_info()

Will cease to happen, heroku won't be adding the database settings, luckly they provided a simple solution. here are the steps i followed for my django app.
Note: i recommend you try this first in a copy of your app, you are using a staging copy right?
Assumptions/Requirements

• heroku gem past 2.18.1. version(this is important, upgrade your gem now)
  gem install heroku
  otherwise you will get a
  No superclass method 'app'
  error
•  Django 1.3 or higher
• You will need a custom buildpack thats updated to account the user_env_compile addon, add it to your app like this
  heroku config:add BUILDPACK_URL=git@github.com:heroku/heroku-buildpack-python.git --app your_app_name
  Or if you need M2Crypto support you will need my custom buildpack that is just a mix of the standard python pack with a guybowdens pack that enabled the support for SWIG needed by M2Crypto.
  heroku config:add BUILDPACK_URL=git://github.com/grillermo/heroku-buildpack-python.git --app your_app_name

Ok now you will have to add a this line to the bottom of your requirements.txt
dj-database-url==0.2.1
Then add the heroku plugin user_env_compile to your app

heroku labs:enable user_env_compile --app your_app_name

And then add the ENV variable to disable injection

heroku config:add DISABLE_INJECTION=1

Now add these lines to your settings.py

import dj_database_url
DATABASES = {'default': dj_database_url.config(default='postgres://localhost')} 

Now make a commit and push to heroku

git commit -m 'disable heroku injection of database settings, manually add them'

git push origin master

You can check is not injecting the settings anymore with:

heroku run cat your_project/settings.py

And at the end of your settings there should not be anything you did not put.
  
References:

• The heroku news article 
• My custom heroku buildpack