Resolving Django-Tenant Subdomain Login Errors with Rest Framework Tokens

Handling Subdomain Login Issues in Django-Tenants with Optimized Schema Queries

Backend solution using Django ORM with explicit schema selection and error handling.

# Import necessary libraries
from django.db import connection
from rest_framework.authtoken.models import Token
from django.contrib.auth import authenticate, login
from django.http import JsonResponse
from django_tenants.utils import schema_context
from django.views.decorators.csrf import csrf_exempt
@csrf_exempt
def dual_login_view(request):
    """Handle login for multi-tenant subdomains with correct schema."""
    if request.method == "POST":
        username = request.POST.get("login")
        password = request.POST.get("password")
        tenant_schema_name = connection.tenant.schema_name
        try:
            # Switch to the correct tenant schema
            with schema_context(tenant_schema_name):
                user = authenticate(request, username=username, password=password)
                if user is not None:
                    login(request, user)
                    # Generate or retrieve token
                    token, created = Token.objects.get_or_create(user=user)
                    return JsonResponse({"status": "success", "token": token.key})
                else:
                    return JsonResponse({"status": "error", "message": "Invalid credentials"}, status=400)
        except Exception as e:
            return JsonResponse({"status": "error", "message": str(e)}, status=500)
    return JsonResponse({"status": "error", "message": "Invalid request method"}, status=405)

Explicit Token Management Using Tenant-Aware Schemas

A modularized and reusable Django API View for login in a multi-tenant architecture.

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
from django.contrib.auth import authenticate
from rest_framework.authtoken.models import Token
from django_tenants.utils import schema_context
class TenantAwareLoginAPIView(APIView):
    """Login endpoint that ensures tenant-aware schema handling."""
    def post(self, request):
        username = request.data.get("username")
        password = request.data.get("password")
        tenant_schema_name = request.tenant.schema_name
        if not username or not password:
            return Response({"error": "Username and password required"}, status=status.HTTP_400_BAD_REQUEST)
        try:
            with schema_context(tenant_schema_name):
                user = authenticate(request, username=username, password=password)
                if user is None:
                    return Response({"error": "Invalid credentials"}, status=status.HTTP_401_UNAUTHORIZED)
                # Generate or retrieve token for the user
                token, created = Token.objects.get_or_create(user=user)
                return Response({"token": f"Token {token.key}"}, status=status.HTTP_200_OK)
        except Exception as e:
            return Response({"error": str(e)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

Frontend Script for Handling Subdomain Login Requests

JavaScript solution to handle form submission and process token-based login for tenant subdomains.

<script>
document.querySelector('form').addEventListener('submit', function(event) {
    event.preventDefault();
    let form = event.target;
    let formData = new FormData(form);
    fetch("{% url 'tenant_aware_login' %}", {
        method: 'POST',
        body: JSON.stringify(Object.fromEntries(formData)),
        headers: {
            'Content-Type': 'application/json',
            'X-CSRFToken': formData.get('csrfmiddlewaretoken')
        }
    })
    .then(response => {
        if (!response.ok) throw new Error('Server Error');
        return response.json();
    })
    .then(data => {
        if (data.token) {
            localStorage.setItem('token', data.token);
            window.location.href = '/';
        } else {
            Swal.fire({
                icon: 'error',
                title: 'Login Failed',
                text: data.error || 'Invalid credentials'
            });
        }
    })
    .catch(error => {
        console.error('Error:', error);
    });
});
</script>

Unit Test to Verify Schema-Aware Token Authentication

Unit test in Python to ensure the API handles schema switching correctly.

from django.test import TestCase
from rest_framework.test import APIClient
from django_tenants.utils import schema_context
from django.contrib.auth.models import User
from rest_framework.authtoken.models import Token
class TenantLoginTest(TestCase):
    def setUp(self):
        self.client = APIClient()
        with schema_context('test_tenant'):  # Switch to tenant schema
            self.user = User.objects.create_user(username='testuser', password='testpass')
    def test_successful_login(self):
        with schema_context('test_tenant'):
            response = self.client.post('/api/login/', {
                'username': 'testuser',
                'password': 'testpass'
            })
            self.assertEqual(response.status_code, 200)
            self.assertIn('token', response.json())
    def test_invalid_login(self):
        with schema_context('test_tenant'):
            response = self.client.post('/api/login/', {
                'username': 'wronguser',
                'password': 'wrongpass'
            })
            self.assertEqual(response.status_code, 401)
            self.assertIn('error', response.json())

Common Questions on Multi-Tenant Django Login Issues

1. What causes a 500 Internal Server Error during login?
2. The error occurs because Token.objects.get_or_create() queries the wrong schema, causing a mismatch when looking up user records.
3. How do I ensure token queries point to the correct tenant schema?
4. Use schema_context() from the django-tenants library to wrap the query execution and switch to the correct schema.
5. Why does the admin panel login work but the user login fails?
6. The Django admin automatically adjusts schema contexts, but custom views using authenticate() or Token.objects may not unless explicitly configured.
7. How do I retrieve and store a login token on the frontend?
8. Use the fetch API to send credentials, then store the response token using localStorage.setItem() for persistent authentication.
9. How can I display better error messages for failed logins?
10. Implement frontend alerts using libraries like SweetAlert2 to notify users of incorrect credentials or server issues.

Ensuring Smooth Login Across Tenant Subdomains

Resolving login failures in Django multi-tenant apps requires ensuring that all database queries operate in the proper schema. By explicitly using tools like schema context, we can guarantee that user tokens are fetched from the correct tenant database, avoiding schema conflicts.

Imagine working on a SaaS platform where users face login failures only on subdomains. With proper schema switching, these issues are resolved, ensuring seamless authentication. Adopting this fix not only improves user experience but also guarantees secure, efficient data access for each tenant. 🔧