Django, Apache 2 and mod_wsgi

A pain in the neck to set up, but nice to have.

1. Follow installation instructions for mod_wsgi and django
2. Add to httpd.conf

      # ----------- Django / WSGI Configuration ----------
       WSGIDaemonProcess processes=2 threads=15
       
       WSGIScriptAlias /mgrm "/home/django/var/www/mgrm/apache/django.wsgi"
       <Directory "/home/django/var/www/mgrm/">
           Order allow,deny
           Allow from all
        </Directory>
       
        Alias "/static/admin" "/opt/python2.7/lib/python2.7/site-packages/django/contrib/admin/media/"
        <Directory "/opt/python2.7/lib/python2.7/site-packages/django/contrib/admin/media/">
            Order allow,deny
            Allow from all
        </Directory>

*Note that the alias for "static/admin" must match whatever alias and path are in the main settings.py file in your Django project directory

3. Create a django.wsgi file in the place that is specified by the path you used in the WSGIScriptAlias that contains the following:


import os
import sys


# Option one
#sys.path.append('/home/django/var/www')
#sys.path.append('/home/django/var/www/mgrm')
#os.environ['DJANGO_SETTINGS_MODULE'] = 'mgrm.settings'
#os.environ['DJANGO_ENV'] = 'PRODUCTION'


# Option two
# from http://blog.dscpl.com.au/2010/03/improved-wsgi-script-for-use-with.html
sys.path.insert(0,'/home/django/var/www/mgrm')
import settings
import django.core.management
django.core.management.setup_environ(settings)
utility = django.core.management.ManagementUtility()
command = utility.fetch_command('runserver')
command.validate()
import django.conf
import django.utils
django.utils.translation.activate(django.conf.settings.LANGUAGE_CODE)


# Common to both options
import django.core.handlers.wsgi


application = django.core.handlers.wsgi.WSGIHandler()


*Note that this file goes inside your django project folder, preferably in an apache folder.

5. Edit main urls.py so that you can use files with both the django server and apache like this:


urlpatterns = patterns('',


    # mod_wsgi does NOT pass the '/mgrm' mount point to this application. However,
    #   the django development server does. So in order to get these urls.py to
    #   work correctly with both, I created a match group that doesn't create a 
    #   back reference. That match group is this: (?:mgrm/)?
    url(r'^(?:mgrm/)?polls/',include('polls.urls')),
    
    # Admin sites are doing some reverse url lookup, and the match group trick
    #   doesn't work with them.  To resolve this issue we create two references:
    #   one for mod_wsgi, and the other for the development server.
    url(r'^admin/',include(admin.site.urls)),
    url(r'^mgrm/admin/', include(admin.site.urls)),
)


6. May need to edit templates to add the application name to each url in the template.

How to get Django to see multiple PostgreSQL schemas

Took awhile to figure this out, so here goes.

First create a PostgreSQL user that will be used by Django to connect to the database.  This is the user that will be included in the settings.py file for the database connection section.

Log into PostgreSQL as admin/superuser and issue the following command:

GRANT USAGE SCHEMA foo TO django_user;


(Or GRANT USAGE to any role which has django_user as a (direct or indirect) member.)
(Or GRANT ALL ... if that is what you want.)

The next step is to change the default schema search path.  To make a permanent change, do the following:

ALTER ROLE django_user SET SEARCH_PATH to "$user",public,your_schema;

Log out and log back in for the change to take effect.  You can test the outcome by doing a \dt and you should see all table from all schemas that the role has been granted access to.

You can now run manage.py inspectdb and it will see all tables in all schemas.  Don't know yet how it will treat tables with the same name in different schemas, as it is no longer required to prefix the schema name in a query, although it can still be done.