升级到2.7后,GAE Python dev服务器间歇性崩溃

Question

我最近将我的GAE Python应用程序升级到Python 2.7.从那时起,我定期与开发服务器发生以下错误,并且开发服务器提供空白页面:

Traceback (most recent call last):
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/runtime/wsgi.py", line 168, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/runtime/wsgi.py", line 206, in _LoadHandler
    handler = __import__(path[0])
  [...]
  File "/Users/joneill/OpenSTV/OpenSTV/trunk/OpaVote-HR/main.py", line 2, in <module>
    import views
  [...]
  File "/Users/joneill/OpenSTV/OpenSTV/trunk/OpaVote-HR/views.py", line 3, in <module>
    from pytz.gae import pytz
  [...]
  File "/Users/joneill/OpenSTV/OpenSTV/trunk/OpaVote-HR/pytz/__init__.py", line 34, in <module>
    from pkg_resources import resource_stream
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 662, in Decorate
    return func(self, *args, **kwargs)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1818, in load_module
    return self.FindAndLoadModule(submodule, fullname, search_path)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 662, in Decorate
    return func(self, *args, **kwargs)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1690, in FindAndLoadModule
    description)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 662, in Decorate
    return func(self, *args, **kwargs)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 1615, in LoadModuleRestricted
    return source_file.load_module(submodule_fullname)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/dist/py_zipimport.py", line 246, in load_module
    submodname, is_package, fullpath, source = self._get_source(fullmodname)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/dist/py_zipimport.py", line 207, in _get_source
    source = self.zipfile.read(relpath.replace(os.sep, '/'))
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.py", line 867, in read
    return self.open(name, "r", pwd).read()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.py", line 882, in open
    zef_file = open(self.filename, 'rb')
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/dev_appserver_import_hook.py", line 578, in __init__
    raise IOError(errno.EACCES, 'file not accessible', filename)
IOError: [Errno 13] file not accessible: '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg'
INFO     2012-01-21 20:50:44,222 dev_appserver.py:2832] "POST /manage HTTP/1.1" 500 -

一些说明:

• 这不会发生在生产服务器上.
• 在开发服务器上,我的应用程序将工作几分钟,然后发生此错误.
• 如果我在开发服务器上停止并重新启动我的应用程序,它将再次运行几分钟.
• 我正在使用最新版本的gae-pytz,你可以看到它在导入时失败了.
• 我删除的[...]类似于你在最后看到的东西.
• 我不知道为什么最后会调用setuptools.
• 我正在使用带狮子的Mac.

我可以使用开发服务器,但每隔几分钟停止并重新启动真的很烦人.任何想法如何解决这一问题？

Answer 1

堆栈跟踪的实际问题是您的代码正在尝试从站点包导入安装工具，而开发服务器不会这样做。

'/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg'

您需要在应用程序代码库中包含 setuptools。事实上，它有时会起作用，这表明您通过各种模块的代码路径有所不同，并且可能（取决于您在开发中的测试）不同的导入顺序意味着安装工具已在其他地方导入，或者仅在代码中的某些点需要。

查看导入 pytz 的堆栈跟踪的第 4 行，下一行是 from pkg_resources import resource_stream 这就是触发其余导入问题的原因。我在项目的根目录使用了一个假的截断的 pkg_resources ，它最终不会尝试从安装工具导入东西。您可以在调试导入模式下运行开发服务器，这会告诉您更多信息

这是一个假的 pkg_resources。

"""Package resource API
--------------------

A resource is a logical file contained within a package, or a logical
subdirectory thereof.  The package resource API expects resource names
to have their path parts separated with ``/``, *not* whatever the local
path separator is.  Do not use os.path operations to manipulate resource
names being passed into the API.

The package resource API is designed to work with normal filesystem packages,
.egg files, and unpacked .egg files.  It can also work in a limited way with
.zip files and with custom PEP 302 loaders that support the ``get_data()``
method.
"""

import sys, os, zipimport, time, re, imp, new

try:
    frozenset
except NameError:
   from sets import ImmutableSet as frozenset

from os import utime   #, rename, unlink    # capture these to bypass sandboxing
from os import open as os_open

可能还有其他/更好的方法可以做到这一点，但它对我有用。

哦，我还建议您使用http://code.google.com/p/gae-pytz/而不是 pytz。

干杯