ModuleNotFoundError-尝试启动服务时没有名为“ main”的模块

Question

内容：

• 我使用Python 3.7创建了Django应用程序。
• 我（正在尝试）使用第二代Google App Engine标准环境。

当我通过运行时，我的应用程序完美运行python manage.py runserver。但是，当我尝试将其部署到Google App Engine时突然停止。

Traceback (most recent call last):
  File "/tmp/tmphgUsp3/lib/python3.7/site-packages/gunicorn/arbiter.py", line 583, in spawn_worker
    worker.init_process()
  File "/tmp/tmphgUsp3/lib/python3.7/site-packages/gunicorn/workers/base.py", line 129, in init_process
    self.load_wsgi()
  File "/tmp/tmphgUsp3/lib/python3.7/site-packages/gunicorn/workers/base.py", line 138, in load_wsgi
    self.wsgi = self.app.wsgi()
  File "/tmp/tmphgUsp3/lib/python3.7/site-packages/gunicorn/app/base.py", line 67, in wsgi
    self.callable = self.load()
  File "/tmp/tmphgUsp3/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 52, in load
    return self.load_wsgiapp()
  File "/tmp/tmphgUsp3/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 41, in load_wsgiapp
    return util.import_app(self.app_uri)
  File "/tmp/tmphgUsp3/lib/python3.7/site-packages/gunicorn/util.py", line 350, in import_app
    __import__(module)
ModuleNotFoundError: No module named 'main'

我经历了无数次讨论，但找不到问题。（作为参考，dev_appserver.py仿真器会产生相同的问题，这是一件好事）。

以下是我的 app.yaml

runtime: python37
env: standard

handlers:
- url: /static
  static_dir: static/
- url: .*
  script: demosite.wsgi.main

我的wsgi.py文件位于以下路径：demosite/wsgi.py其内容如下所示：

import os

from django.core.wsgi import get_wsgi_application

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'demosite.settings')

main = get_wsgi_application()

我的settings.py档案：

import os

class AppSettings(object):
    GoogleCloudProject = os.getenv('GOOGLE_CLOUD_PROJECT')

BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

SECRET_KEY = 'say what?'

DEBUG = True

ALLOWED_HOSTS = [
    '*'
]


INSTALLED_APPS = [
    'anchor.apps.AnchorConfig',
    'crispy_forms',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'demosite.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'demosite.wsgi.main'

try:
    import MySQLdb
except ImportError:
    import pymysql
    pymysql.install_as_MySQLdb()


if os.getenv('SERVER_SOFTWARE', '').startswith('Google App Engine'):
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.mysql',
            'NAME': 'webapp',
            'USER': 'aasdeytst',
            'PASSWORD': 'asdasygetasfasdfasd.',
            'HOST': 'asdgiuasfivaasd',
            'PORT': '3306'
        }
    }
else:
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.mysql',
            'NAME': 'webapp',
            'USER': 'awthdsfhfdhdf',
            'PASSWORD': 'asdasdasdagwdatwt',
            'HOST': 'localhost',
            'PORT': '3306'
        }
    }

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

ANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True

STATIC_ROOT = 'static'
STATIC_URL = '/static/'

CRISPY_TEMPLATE_PACK = 'bootstrap4'

LOGIN_REDIRECT_URL = 'index'
LOGIN_URL = 'login'

SESSION_EXPIRE_AT_BROWSER_CLOSE = False
SESSION_COOKIE_AGE = 1800

我缺少什么，我在做什么错？我花了近4个小时试图解决这个问题，但没有成功。

Answer 1

默认情况下，App Engine app在名为的文件中查找变量main.py。您有两种选择：将WSGI应用程序放置在App Engine期望的位置，或者定义一个自定义入口点：

将您的WSGI应用放置在App Engine期望的位置：

您可以创建一个名为的文件main.py，该文件具有一个app变量，该变量只是从正确的位置导入并以别名命名：

from demosite.wsgi import main as app

添加自定义入口点：

来自https://cloud.google.com/appengine/docs/standard/python3/config/appref：

entrypoint： 可选的。应用启动时执行的命令。为了使您的应用程序接收HTTP请求，entrypoint应包含一个命令，该命令将启动一个Web服务器，该服务器侦听PORT环境变量指定的端口。如果您未指定entrypoint，则App Engine将配置并启动Gunicorn网络服务器。

默认情况下是这样的：

entrypoint: gunicorn -b :$PORT main:app

您将需要以下内容：

entrypoint: gunicorn -b :$PORT demosite.wsgi:main

请参阅此处以获取有关应用程序启动的更多详细信息：https : //cloud.google.com/appengine/docs/standard/python3/runtime#application_startup

Answer 2

添加：

main.py 必须位于应用程序的根目录中，即 app.yaml 所在的位置。

内容也可以是：

   from mysite.wsgi import application

   # App Engine by default looks for a main.py file at the root of the app
   # directory with a WSGI-compatible object called app.
   # This file imports the WSGI-compatible object of your Django app,
   # application from mysite/wsgi.py and renames it app so it is discoverable by
   # App Engine without additional configuration.
   # Alternatively, you can add a custom entrypoint field in your app.yaml:
   # entrypoint: gunicorn -b :$PORT mysite.wsgi
   app = application