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A very slow way to serve Django when all you have is CGI
#!/usr/bin/env python
# encoding: utf-8
"""
django.cgi
A simple cgi script which uses the django WSGI to serve requests.
Code copy/pasted from PEP-0333 and then tweaked to serve django.
http://www.python.org/dev/peps/pep-0333/#the-server-gateway-side
This script assumes django is on your sys.path, and that your site code is at
/home/mycode/mysite. Copy this script into your cgi-bin directory (or do
whatever you need to to make a cgi script executable on your system), and then
update the paths at the bottom of this file to suit your site.
This is probably the slowest way to serve django pages, as the python
interpreter, the django code-base and your site code has to be loaded every
time a request is served. FCGI and mod_python solve this problem, use them if
you can.
In order to speed things up it may be worth experimenting with running
uncompressed zips on the sys.path for django and the site code, as this can be
(theorectically) faster. See PEP-0273 (specifically Benchmarks).
http://www.python.org/dev/peps/pep-0273/
Make sure all python files are compiled in your code base. See
http://docs.python.org/lib/module-compileall.html
"""
import os, sys
# insert a sys.path.append("whatever") in here if django is not
# on your sys.path.
import django.core.handlers.wsgi
def run_with_cgi(application):
environ = dict(os.environ.items())
environ['wsgi.input'] = sys.stdin
environ['wsgi.errors'] = sys.stderr
environ['wsgi.version'] = (1,0)
environ['wsgi.multithread'] = False
environ['wsgi.multiprocess'] = True
environ['wsgi.run_once'] = True
if environ.get('HTTPS','off') in ('on','1'):
environ['wsgi.url_scheme'] = 'https'
else:
environ['wsgi.url_scheme'] = 'http'
headers_set = []
headers_sent = []
def write(data):
if not headers_set:
raise AssertionError("write() before start_response()")
elif not headers_sent:
# Before the first output, send the stored headers
status, response_headers = headers_sent[:] = headers_set
sys.stdout.write('Status: %s\r\n' % status)
for header in response_headers:
sys.stdout.write('%s: %s\r\n' % header)
sys.stdout.write('\r\n')
sys.stdout.write(data)
sys.stdout.flush()
def start_response(status,response_headers,exc_info=None):
if exc_info:
try:
if headers_sent:
# Re-raise original exception if headers sent
raise exc_info[0], exc_info[1], exc_info[2]
finally:
exc_info = None # avoid dangling circular ref
elif headers_set:
raise AssertionError("Headers already set!")
headers_set[:] = [status,response_headers]
return write
result = application(environ, start_response)
try:
for data in result:
if data: # don't send headers until body appears
write(data)
if not headers_sent:
write('') # send headers now if body was empty
finally:
if hasattr(result,'close'):
result.close()
# Change this to the directory above your site code.
sys.path.append("/home/mycode")
# Change mysite to the name of your site package
os.environ['DJANGO_SETTINGS_MODULE'] = 'mysite.settings'
run_with_cgi(django.core.handlers.wsgi.WSGIHandler())
@johnww2-nwxg
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johnww2-nwxg commented Feb 20, 2021

I think this code will not work as you expect:

status, response_headers = headers_sent[:] = headers_set     # 1
sys.stdout.write('Status: %s\r\n' % status)
for header in response_headers:
    sys.stdout.write('%s: %s\r\n' % header)    #2
  1. value of headers_sent is set to headers_set, and slice operation does nothing to change the value
  2. only 1 format arg provided but 3 place holders should throw an exception

let me know if I'm wrong, thanks for sharing your code

@etoulas
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etoulas commented Mar 13, 2022

This is incompatible with Python 3: https://gist.github.com/philchristensen/5845530#file-django-cgi-py-L74
I wrapped this as a tuple (...).

Similarly this line: https://gist.github.com/philchristensen/5845530#file-django-cgi-py-L66
write() expects a string, not bytes. Casting to str() solved this for me.

@etoulas
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etoulas commented Mar 13, 2022

PEP 3333 – Python Web Server Gateway Interface v1.0.1

This is an updated version of PEP 333, modified slightly to improve usability under Python 3, and to incorporate several long-standing de facto amendments to the WSGI protocol. (Its code samples have also been ported to Python 3.)

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