How can I detect multiple logins into a Django web application from different locations?

Question

I want to only allow one authenticated session at a time for an individual login in my Django application. So if a user is logged into the webpage on a given IP address, and those same user credentials are used to login from a different IP address I want to do something (either logout the first user or deny access to the second user.)

Answer 1

Not sure if this is still needed but thought I would share my solution:

1) Install django-tracking (thankyou for that tip Van Gale Google Maps + GeoIP is amazing!)

2) Add this middleware:

from django.contrib.sessions.models import Session
from tracking.models import Visitor
from datetime import datetime

class UserRestrictMiddleware(object):
    """
    Prevents more than one user logging in at once from two different IPs
    """
    def process_request(self, request):
        ip_address = request.META.get('REMOTE_ADDR','')
        try:
            last_login = request.user.last_login
        except:
            last_login = 0
        if unicode(last_login)==unicode(datetime.now())[:19]:
            previous_visitors = Visitor.objects.filter(user=request.user).exclude(ip_address=ip_address)
            for visitor in previous_visitors:
                Session.objects.filter(session_key=visitor.session_key).delete()
                visitor.user = None
                visitor.save()

3) Make sure it goes after the VisitorTrackingMiddleware and you should find previous logins are automatically bumped when someone new logs in :)