使用Django的AppEngine应用程序无法加载

Question

Django经常导致我们的应用程序崩溃。部署之后，应用程序运行良好，但是一旦重新启动/关闭初始实例，它通常会以类似于以下内容的错误启动：

​

Traceback (most recent call last):  File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 266, in Handle
    result = handler(dict(self._environ), self._StartResponse)
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/core/handlers/wsgi.py", line 236, in call
    self.load_middleware()
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/core/handlers/base.py", line 53, in load_middleware
    raise exceptions.ImproperlyConfigured('Error importing middleware %s: "%s"' % (mw_module, e))
ImproperlyConfigured: Error importing middleware myfolder.middleware: "No module named myfolder.middleware"

​

我们的文件结构与此类似：

​

|- app.yaml
|- _ _ init _ _.py
|- settings.py
|- myfolder |
|           |- _ _ init _ _.py
|           |- middleware.py
|           |- ...
|-...
|

​

我们的app.yaml：

​

application: XXXXX
module: app
version: master
runtime: python27
api_version: 1
threadsafe: true

handlers:
- url: /api/(login|logout|passwd|master.|banners.)
  script: app.handler
  secure: always
...

builtins:
- django_wsgi: on

libraries:
- name: django
  version: 1.5

env_variables:
    DJANGO_SETTINGS_MODULE: 'settings'


We have 2 modules in our application and they both exhibit this behaviour (they have similar configurations). Sometimes the modules will stay up for a whole day before crashing again. After they fail to load, all subsequent requests fail with he same error. Deploying one more time always solves the problem temporarily.

We are using plain django with CloudSql. The problem is not reproducible in the development server. After deployment everything in both modules works fine. All middleware, ndb, memcache, cloudsql, taskqueue, etc, including all the modules inside the "myfolder" and every other library xcopied.

The following attempts at solving this problem haven't worked:


We have tried using the appengine_config.py to force django to reload the settings with from django.conf import settings\nsettings._target = None\n
Originally we had shared settings inside "myfolder" and were importing them with "from myfolder.shared_settings import *" inside the root settings.py but django could not load the module myfolder.shared_settings either (similar problem)
using a custom mysettings.py and defining the DJANGO_SETTINGS_MODULE in the app.yaml or in python


The system is not live yet but will be soon and we are running out of options.

Other traces of similarly failing configurations:


Traceback (most recent call last):
  File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 266, in Handle
    result = handler(dict(self._environ), self._StartResponse)
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/core/handlers/wsgi.py", line 236, in __call__
    self.load_middleware()
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/core/handlers/base.py", line 45, in load_middleware
    for middleware_path in settings.MIDDLEWARE_CLASSES:
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/conf/__init__.py", line 53, in __getattr__
    self._setup(name)
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/conf/__init__.py", line 48, in _setup
    self._wrapped = Settings(settings_module)
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/conf/__init__.py", line 134, in __init__
    raise ImportError("Could not import settings '%s' (Is it on sys.path?): %s" % (self.SETTINGS_MODULE, e))
ImportError: Could not import settings 'settings' (Is it on sys.path?): No module named myfolder.settings



Traceback (most recent call last):
  File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 239, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/api/lib_config.py", line 353, in __getattr__
    self._update_configs()
  File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/api/lib_config.py", line 289, in _update_configs
    self._registry.initialize()
  File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/api/lib_config.py", line 164, in initialize
    import_func(self._modname)
  File "/base/data/home/apps/s~blue-myapp/app:master.375531077560785947/appengine_config.py", line 17, in 
    settings._target = None
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/utils/functional.py", line 227, in __setattr__
    self._setup()
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/conf/__init__.py", line 48, in _setup
    self._wrapped = Settings(settings_module)
  File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5/django/conf/__init__.py", line 134, in __init__
    raise ImportError("Could not import settings '%s' (Is it on sys.path?): %s" % (self.SETTINGS_MODULE, e))
ImportError: Could not import settings 'settings' (Is it on sys.path?): No module named myfolder.settings


This is our current appengine_config.py:


import sys
import logging

logging.debug(",\n".join(sys.path))

# Since Google App Engine's webapp framework uses Django templates, Django will half-initialize when webapp is loaded.
# This causes the initialization of the rest of Django's setting to be skipped. If you are getting this error, you need
# to explicitly force Django to reload your settings:

from django.conf import settings
settings._target = None


Logging sys.path from appengine_config.py does not change between a successful instance start and a failed instance start (apart from the XXXXXXXXXXX bit of course):


/base/data/home/apps/s~blue-persomi/app:master.3759720XXXXXXXXXXX,
/base/data/home/runtimes/python27/python27_dist/lib/python27.zip,
/base/data/home/runtimes/python27/python27_dist/lib/python2.7,
/base/data/home/runtimes/python27/python27_dist/lib/python2.7/plat-linux2,
/base/data/home/runtimes/python27/python27_dist/lib/python2.7/lib-tk,
/base/data/home/runtimes/python27/python27_dist/lib/python2.7/lib-old,
/base/data/home/runtimes/python27/python27_dist/lib/python2.7/lib-dynload,
/base/data/home/runtimes/python27/python27_dist/lib/python2.7/site-packages,
/base/data/home/runtimes/python27/python27_lib/versions/1,
/base/data/home/runtimes/python27/python27_lib/versions/third_party/MySQLdb-1.2.4b4,
/base/data/home/runtimes/python27/python27_lib/versions/third_party/django-1.5,
/base/data/home/runtimes/python27/python27_lib/versions/third_party/protorpc-1.0,
/base/data/home/runtimes/python27/python27_lib/versions/third_party/webapp2-2.5.2,
/base/data/home/runtimes/python27/python27_lib/versions/third_party/webob-1.1.1,
/base/data/home/runtimes/python27/python27_lib/versions/third_party/yaml-3.10

Answer 1

这似乎是一个与路径相关的问题，正如人们在你的问题中所提到的那样

可能的短视解决方案将所有东西手动添加到您的路径中--看看这里的最上面的答案：How to import modules in Google App Engine?，至少，这将有助于将问题缩小到与路径相关的范围。

医生是怎么说的：https://developers.google.com/appengine/docs/python/

Python模块包含路径包括应用程序的根目录(包含app.yaml文件的目录)。您在应用程序根目录中创建的模块可以使用根目录中的路径。不要忘记在子目录中创建init.py文件，这样Python就可以将子目录识别为包。

因此，据我所知，b/c的所有内容都位于或低于app.yaml文件，在您的问题中，路径应该已经正确。

1. 再次检查您的所有__init__.py文件是否就位并拼写正确。
2. 尝试删除所有的*.pyc文件并让它们重新生成。
3. 尝试从容器的文件夹名FOLDER_CONTAINING_YAML.myfolder.middleware导入

Answer 2

将下列行添加到您的app.yaml

库：-名称: MySQLdb版本：“最新”

在这里的文件里。https://cloud.google.com/appengine/docs/python/cloud-sql/

理想情况下，它应该被记录在GCM DJANGO指南中。会帮我节省很多时间。

普拉文