Added security and CORS headers

Author: daniel-learns-with-coursera

requirements.txt

@@ -11,6 +11,8 @@ python-dotenv==0.20.0
 # Runtime dependencies
 gunicorn==20.1.0
 honcho==1.1.0
+flask-talisman==0.7.0
+flask-cors==5.0.1
 
 # Code quality
 pylint==2.14.0

service/__init__.py

@@ -8,11 +8,16 @@
 from flask import Flask
 from service import config
 from service.common import log_handlers
+from flask_talisman import Talisman
+from flask_cors import CORS
 
 # Create Flask application
 app = Flask(__name__)
 app.config.from_object(config)
 
+talisman = Talisman(app)
+CORS(app)
+
 # Import the routes After the Flask app is created
 # pylint: disable=wrong-import-position, cyclic-import, wrong-import-order
 from service import routes, models  # noqa: F401 E402

tests/test_routes.py

@@ -12,12 +12,14 @@
 from service.common import status  # HTTP Status Codes
 from service.models import db, Account, init_db
 from service.routes import app
+from service import talisman
 
 DATABASE_URI = os.getenv(
     "DATABASE_URI", "postgresql://postgres:postgres@localhost:5432/postgres"
 )
 
 BASE_URL = "/accounts"
+HTTPS_ENVIRON = {'wsgi.url_scheme': 'https'}
 
 
 ######################################################################
@@ -34,6 +36,7 @@ def setUpClass(cls):
         app.config["SQLALCHEMY_DATABASE_URI"] = DATABASE_URI
         app.logger.setLevel(logging.CRITICAL)
         init_db(app)
+        talisman.force_https = False
 
     @classmethod
     def tearDownClass(cls):
@@ -172,4 +175,24 @@ def test_delete_account(self):
     def test_method_not_allowed(self):
         """It should not allow an illegal method call"""
         resp = self.client.delete(BASE_URL)
-        self.assertEqual(resp.status_code, status.HTTP_405_METHOD_NOT_ALLOWED)
+        self.assertEqual(resp.status_code, status.HTTP_405_METHOD_NOT_ALLOWED)
+
+    def test_security_headers(self):
+        """It should return security headers"""
+        response = self.client.get('/', environ_overrides=HTTPS_ENVIRON)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        headers = {
+            'X-Frame-Options': 'SAMEORIGIN',
+            'X-Content-Type-Options': 'nosniff',
+            'Content-Security-Policy': 'default-src \'self\'',
+            'Referrer-Policy': 'strict-origin-when-cross-origin'
+        }
+        for key, value in headers.items():
+            self.assertEqual(response.headers.get(key), value)
+
+    def test_cors_security(self):
+        """It should return a CORS header"""
+        response = self.client.get('/', environ_overrides=HTTPS_ENVIRON)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        # Check for the CORS header
+        self.assertEqual(response.headers.get('Access-Control-Allow-Origin'), '*')