在 AWS Elastic Beanstalk 上运行 Python Flask 应用程序时出现异常答案

【问题标题】：Exception running Python Flask app on AWS Elastic Beanstalk在 AWS Elastic Beanstalk 上运行 Python Flask 应用程序时出现异常
【发布时间】：2014-04-30 22:02:43
【问题描述】：

我在尝试在 EB 上运行我的 python web 应用程序时遇到了问题。它在本地运行良好，但在 EB 上运行时出现以下异常。问题似乎是它遇到了异常，但是堆栈跟踪是在原始错误之后发生的错误，所以我无法确定根本原因是什么：

Exception on /admin GET
Traceback (most recent call last):
File "/opt/python/run/venv/lib/python2.7/site-packages/flask/app.py", line 1817, in     wsgi_app
response = self.full_dispatch_request()
File "/opt/python/run/venv/lib/python2.7/site-packages/flask/app.py", line 1477, in     full_dispatch_request
rv = self.handle_user_exception(e)
File "/opt/python/run/venv/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/opt/python/run/venv/lib/python2.7/site-packages/flask/app.py", line 1475, in     full_dispatch_request
rv = self.dispatch_request()
File "/opt/python/run/venv/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functionshttp://rule.endpoint(**req.view_args)
File "/opt/python/run/venv/lib/python2.7/site-packages/sandman/sandman.py", line 459, in get_collection
cls = endpoint_class(collection)
File "/opt/python/run/venv/lib/python2.7/site-packages/sandman/sandman.py", line 185, in endpoint_class
cls = current_app.class_referencescollection
File "/opt/python/run/venv/lib/python2.7/site-packages/werkzeug/local.py", line 338, in __getattr__
return getattr(self._get_current_object(), name)
AttributeError: 'Flask' object has no attribute 'class_references'

当我在通过 SSH 连接到我的实例后在端口 5000 上手动启动应用程序并尝试从控制台加载相同的页面时，我没有收到任何错误（并且保存的文件包含正确的 HTML）：

wget http://127.0.0.1:5000/admin
--2014-03-23 17:01:13-- http://127.0.0.1:5000/admin
Connecting to 127.0.0.1:5000... connected.
HTTP request sent, awaiting response... 127.0.0.1 - - 23/Mar/2014 17:01:13 "GET /admin     HTTP/1.1" 301 -
301 MOVED PERMANENTLY
Location: http://127.0.0.1:5000/admin/ following
--2014-03-23 17:01:13-- http://127.0.0.1:5000/admin/
Connecting to 127.0.0.1:5000... connected.
HTTP request sent, awaiting response... 127.0.0.1 - - 23/Mar/2014 17:01:13 "GET /admin/     HTTP/1.1" 200 -
200 OK
Length: 1519 (1.5K) text/html
Saving to: ‘admin’

这是我正在运行的 python 应用程序代码：http://pastebin.com/qgnWz6aK

【问题讨论】：

您是否检查过 Python / Flask / Werkzeug 版本是否与您本地的版本匹配？
Python 在本地和服务器上是 2.7。 flask 和 werkzeug 版本是由 Pip 在 requirements.txt 文件中定义的，所以它们也是一样的。

标签： python flask amazon-elastic-beanstalk

【解决方案1】：

我设法通过使用 Tornado 解决了这个问题（尽管我仍然不确定根本问题是什么）：

from sandman import app
from sandman.model import activate
import logging
import os, sys
from tornado.wsgi import WSGIContainer
from tornado.httpserver import HTTPServer
from tornado.ioloop import IOLoop

app.config['SQLALCHEMY_DATABASE_URI'] = os.environ['DB']

@app.route("/")
def hello():
    return "Hello World!"

if __name__ == "__main__":
    activate(browser=False)
    app.debug = True
    http_server = HTTPServer(WSGIContainer(app))
    http_server.listen(os.environ['PORT'])
    IOLoop.instance().start()

【讨论】：