ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value

I'm in the midst of setting up my Django project on Heroku. I have been following the documentation, but when I foreman start I receive an error that I can't quite figure out. I have set up my engine files, but it doesn't seem to want to work.

Full traceback:

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 399, in execute_from_command_line
    utility.execute()
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 392, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/base.py", line 242, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/base.py", line 285, in execute
    output = self.handle(*args, **options)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/base.py", line 415, in handle
    return self.handle_noargs(**options)
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/core/management/commands/syncdb.py", line 57, in handle_noargs
    cursor = connection.cursor()
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/db/backends/__init__.py", line 160, in cursor
    cursor = self.make_debug_cursor(self._cursor())
  File "/Users/nir/nirla/venv/lib/python2.7/site-packages/django/db/backends/dummy/base.py", line 15, in complain
    raise ImproperlyConfigured("settings.DATABASES is improperly configured. "
django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.

Someone suggested using ./manage.py diffsettings and showing the DATABASES part:

DATABASES = {'default': {'AUTOCOMMIT': True, 'ENGINE': 'django.db.backends.dummy', 'ATOMIC_REQUESTS': False, 'NAME': '', 'TEST_MIRROR': None, 'CONN_MAX_AGE': 0, 'TEST_NAME': None, 'TIME_ZONE': 'UTC', 'TEST_COLLATION': None, 'PORT': '', 'HOST': '', 'USER': '', 'TEST_CHARSET': None, 'PASSWORD': '', 'OPTIONS': {}}}

I can't seem to figure out what it means, but it doesn't look right on the surface.

Here is part of my settings.py that I think could be relevant to this problem:

import os
import dj_database_url

ON_HEROKU = os.environ.get('ON_HEROKU')
HEROKU_SERVER = os.environ.get('HEROKU_SERVER')

if ON_HEROKU:
    
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': 'postgresql',
        }
    }
else:
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
            'USER': '',
            'PASSWORD': '',
            'HOST': '',                      # Empty for localhost through domain sockets or '127.0.0.1' for localhost through TCP.
            'PORT': '',  
        }
    }


DATABASES['default'] =  dj_database_url.config()

SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')

ALLOWED_HOSTS = ['*']

STATIC_URL = '/static/'

# only refers to the location where your static files should end up after running manage.py collectstatic. you shouldn't really need collectstatic) when developing locally
STATIC_ROOT = 'staticfiles'


STATICFILES_DIRS = (    
    os.path.join(BASE_DIR, '../static'),
)

Solution

You are using the dj-database-url module to set DATABASES['default']. Whatever comes before the line:

DATABASES['default'] =  dj_database_url.config()

is meaningless as you replace your database configuration in its entirety. The dj_database_url.config() loads your database configuration from the DATABASE_URL environment variable, or returns {} if the variable is not set.

Judging by your error, you didn't set the DATABASE_URL at all. Judging by the code preceding the dj_database_url.config() line, you should not be using the dj_database_url.config() function at all.

If you did want to use it, at least build a default URL:

if ON_HEROKU:
    DATABASE_URL = 'postgresql://<postgresql>'
else:
    DATABASE_URL = 'sqlite:///' + os.path.join(BASE_DIR, 'db.sqlite3')

DATABASES = {'default': dj_database_url.config(default=DATABASE_URL)}