Django Middleware: log requests and responses

2-minute read

From Django’s context:

Middleware is a framework of hooks into Django’s request/response processing.
It’s a light, low-level “plugin” system for globally altering Django’s input or output.

Middleware is like a layer which processes every request and response. Instead of logging requests and responses in resp. views, its better to do at middleware layer which will log every incoming request. Why better?

it will log unhandled requests/views
one time job, no need to configure for every request/view

Here, we are using Django’s middleware semantics to construct a middleware which will log all requests and corresponding responses.

Create a middleware file

We will create a RequestLogMiddleware class in /middleware/request_log.py in your <application> folder, like:


"""
Middleware to log `*/api/*` requests and responses.
"""
import socket
import time
import json
import logging

request_logger = logging.getLogger(__name__)

class RequestLogMiddleware:
    """Request Logging Middleware."""

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

    def __call__(self, request):
        start_time = time.time()
        log_data = {
            "remote_address": request.META["REMOTE_ADDR"],
            "server_hostname": socket.gethostname(),
            "request_method": request.method,
            "request_path": request.get_full_path(),
        }

        # Only logging "*/api/*" patterns
        if "/api/" in str(request.get_full_path()):
            req_body = json.loads(request.body.decode("utf-8")) if request.body else {}
            log_data["request_body"] = req_body

        response = self.get_response(request)

        if response and response["content-type"] == "application/json":
            response_body = json.loads(response.content.decode("utf-8"))
            log_data["response_body"] = response_body
        log_data["run_time"] = time.time() - start_time

        request_logger.info(msg=log_data)

        return response

    # Log unhandled exceptions as well
    def process_exception(self, request, exception):
        try:
            raise exception
        except Exception as e:
            request_logger.exception("Unhandled Exception: " + str(e))
        return exception

Here we are logging only requests with /api/ in its path. All the processing is done in __call__ method.
Note: Do add __init__.py in middleware folder.

Activate the middleware

Activate the middleware by adding its path in MIDDLEWARE list in your Django’s application settings.py (here: last value):

MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    "django.contrib.sessions.middleware.SessionMiddleware",
    "django.middleware.common.CommonMiddleware",
    "django.contrib.auth.middleware.AuthenticationMiddleware",
    "django.contrib.messages.middleware.MessageMiddleware",
    # Request Logger
    "<application>.middleware.request_log.RequestLogMiddleware",
]

Replace <application> with your application name.

नमस्ते

Django Middleware: log requests and responses

Create a middleware file

Activate the middleware