docs: add Flask receiver example

Author: danihodovic

.env

@@ -1 +1 @@
-export DJANGO_SETTINGS_MODULE=tests.settings
+export DJANGO_SETTINGS_MODULE=tests.settings.test

Dockerfile

@@ -0,0 +1,16 @@
+# syntax=docker/dockerfile:1.3-labs
+FROM python:3.12-bookworm
+
+WORKDIR /app/
+
+RUN pip install --upgrade pip poetry
+
+COPY pyproject.toml poetry.lock /app/
+
+RUN poetry config virtualenvs.create false && poetry install --no-interaction
+
+COPY django_webhook /app/django_webhook
+COPY tests /app/tests
+COPY manage.py /app/manage.py
+
+CMD /app/manage.py runserver_plus 0.0.0.0:8000

README.md

@@ -44,6 +44,7 @@ django-webhook-request-timestamp: 1697818014
 - Admin integration
 - Audit log with past webhook events
 - Protection from replay attacks
+- Allows rotating webhook secrets
 
 ### 📖 Documentation
 

docker-compose.yml

@@ -0,0 +1,49 @@
+services:
+  webhook_server: &defaults
+    build:
+      context: .
+    ports:
+      - "8000:8000"
+    environment:
+      DJANGO_SETTINGS_MODULE: tests.settings
+    volumes:
+      - ./tests:/app/tests
+      - ./django_webhook:/app/django_webhook
+
+  webhook_worker:
+    <<: *defaults
+    ports: []
+    command: celery --app tests.celery_app:app worker --loglevel=INFO
+
+  postgres:
+    image: postgres:14
+    container_name: postgres
+    environment:
+      POSTGRES_DB: postgres
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+    ports: ['5432:5432']
+
+  redis:
+    image: redis
+    ports:
+      - "6379:6379"
+
+  nodejs_receiver:
+    build:
+      context: examples/nodejs
+    ports:
+      - "8001:8001"
+
+  flask_receiver:
+    build:
+      context: examples/flask
+    ports:
+      - "8002:8002"
+    volumes:
+      - ./examples/flask:/app/
+
+volumes:
+  pgdata:

examples/flask/Dockerfile

@@ -0,0 +1,10 @@
+# syntax=docker/dockerfile:1.3-labs
+FROM python:3.12-bookworm
+
+WORKDIR /app/
+
+RUN pip install --upgrade pip flask
+
+COPY server.py /app/server.py
+
+CMD flask --app server.py --debug run --host 0.0.0.0 --port 8002

examples/flask/server.py

@@ -0,0 +1,30 @@
+import hmac
+from hashlib import sha256
+
+from flask import Flask, Response, request
+
+app = Flask(__name__)
+
+webhook_secret = "very-secret-token"
+
+
+@app.route("/webhook", methods=["POST"])
+def webhook():
+    signatures_str = request.headers.get("Django-Webhook-Signature-v1", "")
+    signatures = signatures_str.split(",")
+    timestamp = request.headers["Django-Webhook-Request-Timestamp"]
+
+    for signature in signatures:
+        digest_payload = bytes(timestamp, "utf8") + b":" + request.data
+        digest = hmac.new(
+            key=webhook_secret.encode(),
+            msg=digest_payload,
+            digestmod=sha256,
+        )
+        signature_valid = hmac.compare_digest(digest.hexdigest(), signature)
+        if not signature_valid:
+            app.logger.warning("Invalid signature from incoming webhook")
+            return Response("Invalid signature", status=400)
+
+    app.logger.info(request.json)
+    return Response("Webhook received.", status=200)

manage.py

@@ -5,7 +5,7 @@
 import sys
 
 if __name__ == "__main__":
-    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "tests.settings")
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "tests.settings.local")
     from django.core.management import execute_from_command_line
 
     execute_from_command_line(sys.argv)

mypy.ini

@@ -4,7 +4,7 @@ ignore_missing_imports = True
 plugins = mypy_django_plugin.main
 
 [mypy.plugins.django-stubs]
-django_settings_module = tests.settings
+django_settings_module = tests.settings.test
 
 [mypy-webhooks.migrations.*]
 ignore_errors = True