Apache CGI in user directory “End of script output before headers”

Question

I know there are some questions about this topic, but none seems to solve my issue. See this or this or this.

I\'m on Linux, Fedora21, and I\'m trying to enable per user

Answer 1

Try running your script as the apache user.

There are a number of reasons this could be happening. @JimB mentions problem with the shebang. @premganz mentions problems with debug print statements that fire before your Content-Type string is written. In my case it was a db connection failure. It could be any other problem.

I found the best way to debug this is to run the script directly as the apache user on the command line, and see what errors it gives.

How to run your script as the Apache user

Assuming you're running apache2, and the apache user is www-data, and your cgi script is /myapp/myreport.py - you can do the following.

1. Allow logins as the www-data user, by changing its default shell. Edit /etc/passwd (temporarily)

   sudo su - 
   cd /etc
   cp -p passwd passwd.2017-10-22
   
   emacs passwd     # edit file - use your favorite editor
   

   Change:

   www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
   

   To:

   www-data:x:33:33:www-data:/var/www:/bin/bash
   

2. Log in as the www-data user

   sudo su - www-data
   

3. Set any environment vars. Convert your apache SetEnv statements to export statements. In my case, my apache config directory settings has these vars set

   SetEnv PYTHONPATH /myapp/lib
   SetEnv VCONF /myapp/conf/prod.yaml
   

   Run them as

   export PYTHONPATH=/myapp/lib
   export VCONF=/myapp/conf/prod.yaml
   

4. Then try your cgi script

   cd /myapp
   ./myreport.py
   

5. You should see whatever error Apache is experiencing. FIX THEM.

6. Set the www-data user's default shell back to /usr/sbin/nologin