AppRegistryNotReady：应用程序尚未加载。Django

Question

我正在尝试在Google App Engine上运行Django 1.9。当我通过Google API Explorer访问API时，出现了以下错误：

Traceback (most recent call last):
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 96, in LoadObject
    __import__(cumulative_path)
  File "/home/gemini/projects/cityguide-backend/src/cityguide/api/services.py", line 9, in <module>
    from cityguide.api.internal.categories import Categories
  File "/home/gemini/projects/cityguide-backend/src/cityguide/api/internal/categories.py", line 10, in <module>
    from cityguide.models import Category
  File "/home/gemini/projects/cityguide-backend/src/cityguide/models.py", line 8, in <module>
    class ContactDetails(models.Model):
  File "/home/gemini/projects/cityguide-backend/src/lib/django/db/models/base.py", line 94, in __new__
    app_config = apps.get_containing_app_config(module)
  File "/home/gemini/projects/cityguide-backend/src/lib/django/apps/registry.py", line 239, in get_containing_app_config
    self.check_apps_ready()
  File "/home/gemini/projects/cityguide-backend/src/lib/django/apps/registry.py", line 124, in check_apps_ready
    raise AppRegistryNotReady("Apps aren't loaded yet.")
AppRegistryNotReady: Apps aren't loaded yet.

我已经添加了。

builtins:
- deferred: on
- remote_api: on
- django_wsgi: on

handlers:
 - url: .*
   script: mysite.wsgi.application

env_variables:
  DJANGO_SETTINGS_MODULE: 'mysite.settings'

在 app.yaml 文件中。

wsgi.py 的样子如下：

import os

from django.core.wsgi import get_wsgi_application
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "mysite.settings")

application = get_wsgi_application()

我尝试在models.py的顶部添加django.setup()代码，但出现了不同的错误。

ERROR    2016-02-01 10:03:02,918 wsgi.py:263] 
Traceback (most recent call last):
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 96, in LoadObject
    __import__(cumulative_path)
  File "/home/gemini/projects/cityguide-backend/src/cityguide/api/services.py", line 9, in <module>
    from cityguide.api.internal.categories import Categories
  File "/home/gemini/projects/cityguide-backend/src/cityguide/api/internal/categories.py", line 10, in <module>
    from cityguide.models import Category
  File "/home/gemini/projects/cityguide-backend/src/cityguide/models.py", line 6, in <module>
    django.setup()
  File "/home/gemini/projects/cityguide-backend/src/lib/django/__init__.py", line 18, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/gemini/projects/cityguide-backend/src/lib/django/apps/registry.py", line 115, in populate
    app_config.ready()
  File "/home/gemini/projects/cityguide-backend/src/lib/django/contrib/admin/apps.py", line 22, in ready
    self.module.autodiscover()
  File "/home/gemini/projects/cityguide-backend/src/lib/django/contrib/admin/__init__.py", line 26, in autodiscover
    autodiscover_modules('admin', register_to=site)
  File "/home/gemini/projects/cityguide-backend/src/lib/django/utils/module_loading.py", line 50, in autodiscover_modules
    import_module('%s.%s' % (app_config.name, module_to_search))
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/gemini/projects/cityguide-backend/src/cityguide/admin.py", line 2, in <module>
    from cityguide.models import Category
ImportError: cannot import name Category
ERROR    2016-02-01 10:03:02,919 wsgi.py:263] 
Traceback (most recent call last):
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 96, in LoadObject
    __import__(cumulative_path)
  File "/home/gemini/projects/cityguide-backend/src/cityguide/api/services.py", line 9, in <module>
    from cityguide.api.internal.categories import Categories
  File "/home/gemini/projects/cityguide-backend/src/cityguide/api/internal/categories.py", line 10, in <module>
INFO     2016-02-01 10:03:03,000 module.py:794] default: "POST /_ah/spi/BackendService.getApiConfigs HTTP/1.1" 500 -
    from cityguide.models import Category
INFO     2016-02-01 10:03:03,001 module.py:794] default: "POST /_ah/spi/BackendService.getApiConfigs HTTP/1.1" 500 -
  File "/home/gemini/projects/cityguide-backend/src/cityguide/models.py", line 6, in <module>
INFO     2016-02-01 10:03:03,001 module.py:794] default: "GET /_ah/api/discovery/v1/apis HTTP/1.1" 500 60
    django.setup()
INFO     2016-02-01 10:03:03,001 module.py:794] default: "GET /_ah/api/discovery/v1/apis HTTP/1.1" 500 60
  File "/home/gemini/projects/cityguide-backend/src/lib/django/__init__.py", line 18, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/gemini/projects/cityguide-backend/src/lib/django/apps/registry.py", line 78, in populate
    raise RuntimeError("populate() isn't reentrant")
RuntimeError: populate() isn't reentrant

这个问题的临时解决方案：

看起来我需要首先打开主页。这样它会加载数据库，因为我让主页返回所有数据库表内容。一旦数据库列表显示在主页上，我们就可以准备调用Google API Explorer了。

有没有办法改进这个解决方案？

- Avinash Raj

---

错误信息通常意味着 application = get_wsgi_application() 没有运行。例如，如果您直接导入 Django 模型。我认为需要一些设置过程来将 Python 模型连接到数据库。 - Håken Lid

我不确定在这一步File "/home/gemini/softwares/google_appengine/google/appengine/runtime/wsgi.py", line 96, in LoadObject __import__(cumulative_path)会发生什么，但它肯定是来自于django项目中不同的wsgi.py文件。也许get_wsgi_application()步骤还没有运行。 - Håken Lid

@AvinashRaj 如果您尝试使用Django的manage.py runserver运行您的网站，它是否有效？ - Louis

@Louis 不，它不会。 - Avinash Raj

Answer 1

你应该在脚本中这样启动Django：

import django
django.setup()

请查看https://docs.djangoproject.com/en/1.9/ref/applications/#django.setup。

您还可以查看链接中的“故障排除”部分，以查看解决此特定异常的其他可能性。

将上述两行添加到services.py文件顶部，可解决我的问题。

- Mijamo

---

您IP地址为143.198.54.68，由于运营成本限制，当前对于免费用户的使用频率限制为每个IP每72小时10次对话，如需解除限制，请点击左下角设置图标按钮（手机用户先点击左上角菜单按钮）。 - Håken Lid

@HåkenLid 请看我的更新... 我已经添加了一个临时解决方案。 - Avinash Raj

@AvinashRaj 我无法提供更好的永久解决方案。我从未在Google应用引擎或Google API浏览器中使用过Django。 - Håken Lid

Answer 2

在你的脚本中，将 Django 初始化为：

from django_root_app.wsgi import application

- FelipeGTX