Running Multiple Django Sites in a Single WSGI Process via Dynamic Host Routing

When operating a multi-brand SaaS platform or white-label web portfolio, spinning up separate Gunicorn/uWSGI worker pools for every domain wastes RAM. Instead, a single Django WSGI process can serve multiple distinct domains and URL configurations dynamically based on the incoming Host header.

1. Custom Host-Routing Middleware in Django

In Django, setting request.urlconf inside a middleware class before URL resolution overrides settings.ROOT_URLCONF for that specific request thread/coroutine:

class MultiHostUrlConfMiddleware:
    HOST_URLCONF_MAP = {
        "www.aldianfazrihady.com": "afcom.urls",
        "cello.aldianfazrihady.com": "cello.urls",
        "payflow-hosted-page.aldianfazrihady.com": "payflow_hosted_page.urls",
    }

    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        host = request.get_host().split(":")[0].lower()
        urlconf = self.HOST_URLCONF_MAP.get(host)
        if urlconf:
            request.urlconf = urlconf
        return self.get_response(request)

2. Cache Key Isolation & CSRF Trusted Origins

• Cache Key Prefixing: Always include the current request.get_host() in your custom KEY_FUNCTION so Django's per-site or view cache never serves HTML rendered for Domain A to a visitor on Domain B.
• Allowed Hosts & CSRF: List all white-label domains in ALLOWED_HOSTS and CSRF_TRUSTED_ORIGINS, and scope session cookies appropriately.