Django 1.11：WSGI设置环境变量后Settings文件无法获取问题

Hey there, let's break down why your environment variables aren't showing up in your Django settings file, and how to fix it.

The Root Cause #

Looking at your current wsgi.py code, the key issue is the order of operations:

• You're calling get_wsgi_application() before you handle passing the WSGI environment variables into os.environ.
• Django loads your settings file the moment get_wsgi_application() runs. That means when your settings try to read VAR_1 or VAR_2, those variables haven't been added to the environment yet—so they're nowhere to be found.

The Fixed wsgi.py Code #

Here's the adjusted version that ensures your environment variables are available when Django loads its settings:

# -*- coding: utf-8 -*-
import os
import sys
from django.core.wsgi import get_wsgi_application

PATH = os.path.abspath(os.path.join(os.path.dirname(os.path.abspath(__file__))))
if PATH not in sys.path:
    sys.path.append(PATH)

# Define which WSGI environment variables to pass through
ENV_VARIABLES_TO_PASS = ['VAR_1', 'VAR_2']

def application(environ, start_response):
    # Inject WSGI environment variables into os.environ FIRST
    for var_name in ENV_VARIABLES_TO_PASS:
        if var_name in environ:
            os.environ[var_name] = environ[var_name]
    
    # Now load the Django WSGI application (this triggers settings loading)
    django_application = get_wsgi_application()
    return django_application(environ, start_response)

# Set your settings module before anything else
os.environ['DJANGO_SETTINGS_MODULE'] = 'cms.settings.qa'

Key Changes Explained #

• We moved the get_wsgi_application() call inside the application function, right after we inject the environment variables. This ensures Django loads settings only after the variables are available in os.environ.
• We kept the DJANGO_SETTINGS_MODULE assignment at the bottom (you could also put it inside the application function if needed—just make sure it's before get_wsgi_application()).
• We added a check to only copy variables that actually exist in the WSGI environ dictionary, avoiding overwriting existing variables with None if they're missing.

Testing It Out #

Once you update your wsgi.py, you can verify the variables are accessible in your settings file by adding something like this temporarily:

# In cms/settings/qa.py
import os
print("VAR_1 value:", os.environ.get('VAR_1'))
print("VAR_2 value:", os.environ.get('VAR_2'))

Just remember to remove those print statements once you confirm it's working!

内容的提问来源于stack exchange，提问作者Yossi Shaish