[解決済み] Django ImproperlyConfigured: SECRET_KEY 設定は空であってはいけません。

質問事項

いくつかの基本設定を含む複数の設定ファイル（開発、本番、...）をセットアップしようとしています。しかし、成功しません。以下のコマンドを実行すると ./manage.py runserver 以下のようなエラーが発生します。

(cb)clime@den /srv/www/cb $ ./manage.py runserver
ImproperlyConfigured: The SECRET_KEY setting must not be empty.

これが私の設定モジュールです。

(cb)clime@den /srv/www/cb/cb/settings $ ll
total 24
-rw-rw-r--. 1 clime clime 8230 Oct  2 02:56 base.py
-rw-rw-r--. 1 clime clime  489 Oct  2 03:09 development.py
-rw-rw-r--. 1 clime clime   24 Oct  2 02:34 __init__.py
-rw-rw-r--. 1 clime clime  471 Oct  2 02:51 production.py

基本設定(SECRET_KEYを含む)。

(cb)clime@den /srv/www/cb/cb/settings $ cat base.py:
# Django base settings for cb project.

import django.conf.global_settings as defaults

DEBUG = False
TEMPLATE_DEBUG = False

INTERNAL_IPS = ('127.0.0.1',)

ADMINS = (
    ('clime', '[email protected]'),
)

MANAGERS = ADMINS

DATABASES = {
    'default': {
        #'ENGINE': 'django.db.backends.postgresql_psycopg2', # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'.
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'cwu',                   # Or path to database file if using sqlite3.
        'USER': 'clime',                 # Not used with sqlite3.
        'PASSWORD': '',                  # Not used with sqlite3.
        'HOST': '',                      # Set to empty string for localhost. Not used with sqlite3.
        'PORT': '',                      # Set to empty string for default. Not used with sqlite3.
    }
}

# Local time zone for this installation. Choices can be found here:
# http://en.wikipedia.org/wiki/List_of_tz_zones_by_name
# although not all choices may be available on all operating systems.
# In a Windows environment this must be set to your system time zone.
TIME_ZONE = 'Europe/Prague'

# Language code for this installation. All choices can be found here:
# http://www.i18nguy.com/unicode/language-identifiers.html
LANGUAGE_CODE = 'en-us'

SITE_ID = 1

# If you set this to False, Django will make some optimizations so as not
# to load the internationalization machinery.
USE_I18N = False

# If you set this to False, Django will not format dates, numbers and
# calendars according to the current locale.
USE_L10N = False # TODO: make this true and accustom date time input

DATE_INPUT_FORMATS = defaults.DATE_INPUT_FORMATS + ('%d %b %y', '%d %b, %y') # + ('25 Oct 13', '25 Oct, 13')

# If you set this to False, Django will not use timezone-aware datetimes.
USE_TZ = True

# Absolute filesystem path to the directory that will hold user-uploaded files.
# Example: "/home/media/media.lawrence.com/media/"
MEDIA_ROOT = '/srv/www/cb/media'

# URL that handles the media served from MEDIA_ROOT. Make sure to use a
# trailing slash.
# Examples: "http://media.lawrence.com/media/", "http://example.com/media/"
MEDIA_URL = '/media/'

# Absolute path to the directory static files should be collected to.
# Don't put anything in this directory yourself; store your static files
# in apps' "static/" subdirectories and in STATICFILES_DIRS.
# Example: "/home/media/media.lawrence.com/static/"
STATIC_ROOT = '/srv/www/cb/static'

# URL prefix for static files.
# Example: "http://media.lawrence.com/static/"
STATIC_URL = '/static/'

# Additional locations of static files
STATICFILES_DIRS = (
    # Put strings here, like "/home/html/static" or "C:/www/django/static".
    # Always use forward slashes, even on Windows.
    # Don't forget to use absolute paths, not relative paths.
)

# List of finder classes that know how to find static files in
# various locations.
STATICFILES_FINDERS = (
    'django.contrib.staticfiles.finders.FileSystemFinder',
    'django.contrib.staticfiles.finders.AppDirectoriesFinder',
#    'django.contrib.staticfiles.finders.DefaultStorageFinder',
)

# Make this unique, and don't share it with anybody.
SECRET_KEY = '8lu*6g0lg)9z!ba+a$ehk)xt)x%rxgb$i1&022shmi1jcgihb*'

# List of callables that know how to import templates from various sources.
TEMPLATE_LOADERS = (
    'django.template.loaders.filesystem.Loader',
    'django.template.loaders.app_directories.Loader',
#     'django.template.loaders.eggs.Loader',
)

TEMPLATE_CONTEXT_PROCESSORS = (
    'django.contrib.auth.context_processors.auth',
    'django.core.context_processors.request',
    'django.core.context_processors.debug',
    'django.core.context_processors.i18n',
    'django.core.context_processors.media',
    'django.core.context_processors.static',
    'django.core.context_processors.tz',
    'django.contrib.messages.context_processors.messages',
    'web.context.inbox',
    'web.context.base',
    'web.context.main_search',
    'web.context.enums',
)

MIDDLEWARE_CLASSES = (
    'django.middleware.common.CommonMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'watson.middleware.SearchContextMiddleware',
    'debug_toolbar.middleware.DebugToolbarMiddleware',
    'middleware.UserMemberMiddleware',
    'middleware.ProfilerMiddleware',
    'middleware.VaryOnAcceptMiddleware',
    # Uncomment the next line for simple clickjacking protection:
    # 'django.middleware.clickjacking.XFrameOptionsMiddleware',
)

ROOT_URLCONF = 'cb.urls'

# Python dotted path to the WSGI application used by Django's runserver.
WSGI_APPLICATION = 'cb.wsgi.application'

TEMPLATE_DIRS = (
    # Put strings here, like "/home/html/django_templates" or "C:/www/django/templates".
    # Always use forward slashes, even on Windows.
    # Don't forget to use absolute paths, not relative paths.
    '/srv/www/cb/web/templates',
    '/srv/www/cb/templates',
)

INSTALLED_APPS = (
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'south',
    'grappelli', # must be before admin
    'django.contrib.admin',
    'django.contrib.admindocs',
    'endless_pagination',
    'debug_toolbar',
    'djangoratings',
    'watson',
    'web',
)

AUTH_USER_MODEL = 'web.User'

# A sample logging configuration. The only tangible logging
# performed by this configuration is to send an email to
# the site admins on every HTTP 500 error when DEBUG=False.
# See http://docs.djangoproject.com/en/dev/topics/logging for
# more details on how to customize your logging configuration.
LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'filters': {
        'require_debug_false': {
            '()': 'django.utils.log.RequireDebugFalse'
        }
    },
    'formatters': {
        'standard': {
            'format' : "[%(asctime)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s",
            'datefmt' : "%d/%b/%Y %H:%M:%S"
        },
    },
    'handlers': {
        'mail_admins': {
            'level': 'ERROR',
            'filters': ['require_debug_false'],
            'class': 'django.utils.log.AdminEmailHandler'
        },
        'null': {
            'level':'DEBUG',
            'class':'django.utils.log.NullHandler',
        },
        'logfile': {
            'level':'DEBUG',
            'class':'logging.handlers.RotatingFileHandler',
            'filename': "/srv/www/cb/logs/application.log",
            'maxBytes': 50000,
            'backupCount': 2,
            'formatter': 'standard',
        },
        'console':{
            'level':'INFO',
            'class':'logging.StreamHandler',
            'formatter': 'standard'
        },
    },
    'loggers': {
        'django.request': {
            'handlers': ['mail_admins'],
            'level': 'ERROR',
            'propagate': True,
        },
        'django': {
            'handlers':['console'],
            'propagate': True,
            'level':'WARN',
        },
        'django.db.backends': {
            'handlers': ['console'],
            'level': 'DEBUG',
            'propagate': False,
        },
        'web': {
            'handlers': ['console', 'logfile'],
            'level': 'DEBUG',
        },
    },
}

LOGIN_URL = 'login'
LOGOUT_URL = 'logout'

#ENDLESS_PAGINATION_LOADING = """
#    <img src="/static/web/img/preloader.gif" alt="loading" style="margin:auto"/>
#"""
ENDLESS_PAGINATION_LOADING = """
    <div class="spinner small" style="margin:auto">
        <div class="block_1 spinner_block small"></div>
        <div class="block_2 spinner_block small"></div>
        <div class="block_3 spinner_block small"></div>
    </div>
"""

DEBUG_TOOLBAR_CONFIG = {
    'INTERCEPT_REDIRECTS': False,
}

import django.template.loader
django.template.loader.add_to_builtins('web.templatetags.cb_tags')
django.template.loader.add_to_builtins('web.templatetags.tag_library')

WATSON_POSTGRESQL_SEARCH_CONFIG = 'public.english_nostop'

設定ファイルの1つです。

(cb)clime@den /srv/www/cb/cb/settings $ cat development.py 
from base import *

DEBUG = True
TEMPLATE_DEBUG = True

ALLOWED_HOSTS = ['127.0.0.1', '31.31.78.149']

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'cwu',
        'USER': 'clime',
        'PASSWORD': '',
        'HOST': '',
        'PORT': '',
    }
}

MEDIA_ROOT = '/srv/www/cb/media/'

STATIC_ROOT = '/srv/www/cb/static/'

TEMPLATE_DIRS = (
    '/srv/www/cb/web/templates',
    '/srv/www/cb/templates',
)

のコード manage.py :

(cb)clime@den /srv/www/cb $ cat manage.py 
#!/usr/bin/env python
import os
import sys

if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "cb.settings.development")

    from django.core.management import execute_from_command_line

    execute_from_command_line(sys.argv)

を追加すると from base import * を /srv/www/cb/cb/settings/__init__.py (それ以外は空)すると、魔法のように動き出すのですが、なぜなのか理解できません。どなたか、ここで何が起こっているのか説明してください。Pythonモジュールのマジックに違いありません。

EDITです。 また、base.pyからこの行を削除すると、すべてが動作するようになります。

django.template.loader.add_to_builtins('web.templatetags.cb_tags')

web.templatetags.cb_tags からこの行を削除すると、それも動作するようになります。

from endless_pagination.templatetags import endless

につながるからでしょうか。

from django.conf import settings
PER_PAGE = getattr(settings, 'ENDLESS_PAGINATION_PER_PAGE', 10)

それで、変な円形が出来てゲームオーバー。

解決方法は？

私は同じエラーに遭遇し、それは設定によってロードされたモジュールまたはクラスと設定モジュール自体の間の循環依存関係であることが判明した。私の場合、それはsettingsで名付けられたミドルウェア・クラスで、それ自身がsettingsをロードしようとしたのです。