Django，Python 3和Postgres - mod_wsgi問題

Question

我正在嘗試為個人項目配置Django測試應用程序。 我之前有Django的經驗，但這完全是Python 2.7.x. 我想盡可能開始使用3.x，這個項目似乎是一個很好的開始。

Backend是一個標准的Postgres 9.4安裝，Apache 2.4，Python 3.4在virtualenvwrapper中，操作系統是OSX 10.10。 mod_wsgi和mod_wsgi3都是通過homebrew安裝的。

但是，有問題讓mod_wsgi和mod_wsgi3與python 3一起使用。具體來說，。/ ./manage.py runserver 8080工作正常，但是當我嘗試使用Apache的虛擬主機配置時，我得到了

mod_wsgi (pid=29906): Target WSGI script '/Users/jason/projects/geocode_django/geodjango/geodjango/wsgi.py' cannot be loaded as Python module.
mod_wsgi (pid=29906): Exception occurred processing WSGI script '/Users/jason/projects/geocode_django/geodjango/geodjango/wsgi.py'.
Traceback (most recent call last):
    File "/Users/jason/projects/geocode_django/geodjango/geodjango/wsgi.py", line 28, in <module>
    application = get_wsgi_application()
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/core/wsgi.py", line 14, in       get_wsgi_application
      django.setup()
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/__init__.py", line 21, in setup
      apps.populate(settings.INSTALLED_APPS)
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/apps/registry.py", line 108, in populate
     app_config.import_models(all_models)
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/apps/config.py", line 197, in import_models
      self.models_module = import_module(models_module_name)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
       __import__(name)
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/contrib/auth/models.py", line 40, in <module>
       class Permission(models.Model):
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/db/models/base.py", line 125, in __new__
       new_class.add_to_class('_meta', Options(meta, **kwargs))
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/db/models/base.py", line 300, in add_to_class
       value.contribute_to_class(cls, name)
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/db/models/options.py", line 166, in contribute_to_class
       self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/db/__init__.py", line 40, in __getattr__
       return getattr(connections[DEFAULT_DB_ALIAS], item)
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/db/utils.py", line 242, in __getitem__
        backend = load_backend(db['ENGINE'])
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/db/utils.py", line 108, in load_backend
        return import_module('%s.base' % backend_name)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
        __import__(name)
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/contrib/gis/db/backends/postgis/base.py", line 2, in <module>
        from django.db.backends.postgresql_psycopg2.base import DatabaseWrapper as Psycopg2DatabaseWrapper
    File "/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 27, in <module>
        raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
          ImproperlyConfigured: Error loading psycopg2 module: dlopen(/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/  site-packages/psycopg2/_psycopg.so, 2): Symbol not found: _PyBytes_Type
        Referenced from: /Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/psycopg2/_psycopg.so
          Expected in: flat namespace
          in /Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages/psycopg2/_psycopg.so

我的wsgi.py文件是

import os, sys, site

site.addsitedir("/Users/jason/.virtualenvs/geodev_env3/lib/python3.4/site-packages")

sys.path.append("/Users/jason/projects/geocode_django/geodjango")
sys.path.append("/Users/jason/projects/geocode_django/geodjango/geodjango")

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "geodjango.settings")

with open("/Users/jason/.virtualenvs/geodev_env3/bin/activate_this.py") as f:
    code = compile(f.read(), "/Users/jason/.virtualenvs/geodev_env3/bin/activate_this.py", "exec")
    exec(code, dict(__file__="/Users/jason/.virtualenvs/geodev_env3/bin/activate_this.py"))

from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()

和virtualhost文件是：

LoadModule wsgi_module /usr/local/Cellar/mod_wsgi3/3.5/libexec/mod_wsgi.so

<VirtualHost *:80>
    ServerName      dev.geocode.com
    ServerAlias     geocode.com
    ServerAdmin     jason@someschool.edu

    DocumentRoot    "/Users/jason/projects/geocode_django"
    Alias /static/ /Users/jason/projects/geocode_django/static/

    WSGIScriptAlias / /Users/jason/projects/geocode_django/geodjango/geodjango/wsgi.py

    <Directory /Users/jason/projects/geocode_django/static >
            require all granted
    </Directory>

    <Directory /Users/jason/projects/geocode_django/geodjango/geodjango >
            <Files wsgi.py >
                    Require all granted
            </Files>

    </Directory>

    CustomLog /Users/jason/projects/geocode_django/logs/access.log combined
    ErrorLog /Users/jason/projects/geocode_django/logs/error.log

</VirtualHost>

我的問題是，如果我有一個python 2.7 virtualenv與相同的虛擬主機與LoadModule指向

LoadModule wsgi_module /usr/local/Cellar/mod_wsgi/4.4.7/libexec/mod_wsgi.so

並替換

with open("/Users/jason/.virtualenvs/geodev_env3/bin/activate_this.py") as f:
    code = compile(f.read(), "/Users/jason/.virtualenvs/geodev_env3/bin/activate_this.py", "exec")
    exec(code, dict(__file__="/Users/jason/.virtualenvs/geodev_env3/bin/activate_this.py"))

在wsgi.py中

exec(open("/Users/jasonjohns/.virtualenvs/geocode_env/bin/activate_this.py").read())

我可以使用URL dev.geocode.com加載該站點。 否則，我在日志文件中收到錯誤輸出錯誤500頁。

我原本以為這是psycopg2的一個問題，並提交了一個錯誤報告 。 但是，開發人員關注mod_wsgi，而不是psycopg。

沒有為我的本地環境編譯mod_wsgi，有沒有辦法解決這個問題？

Answer 1

通過mod_wsgi google組從Graham Dumpleton獲得提示，找到了解決方案。 核心問題是，版本mod_wsgi通過同時安裝brew install mod_wsgi和pip install mod_wsgi全部編譯為Python 2.7.x.

另一件事。 pip ，在python --version返回Python 2.7.6的系統上，將使用該Python版本來構建任何安裝命令。 如果你有Python 3.x，並且2.7.x和python --version返回Python 3.xx ， pip3 install ...將下載3.x兼容代碼並為該Python版本構建。

解決方案是通過刪除兩個安裝

brew uninstall mod_wsgi
pip uninstall mod_wsgi

並安裝通過

pip3 install mod_wsgi

因此，Apache配置文件的LoadModule位置已更改為

/usr/local/lib/python3.4/site-packages/mod_wsgi-4.4.9-py3.4-macosx-10.10-x86_64.egg/mod_wsgi/server/mod_wsgi-py34.so

注意路徑中的python3.4位置。

進行這些更改並重新啟動Apache后，該站點將按預期加載。