Turn off tracking unless HTTPBIN_TRACKING is set.

Fixes #245.

AUTHORS

@@ -21,3 +21,4 @@ Patches and Suggestions
 - Cory Benfield (Lukasa) <cory@lukasa.co.uk>
 - Matt Robenolt (https://github.com/mattrobenolt)
 - Dave Challis (https://github.com/davechallis)
+- Florian Bruhin (https://github.com/The-Compiler)

httpbin/core.py

@@ -93,7 +93,7 @@ def set_cors_headers(response):
 def view_landing_page():
     """Generates Landing Page."""
 
-    return render_template('index.html')
+    return render_template('index.html', env=os.environ)
 
 
 @app.route('/html')

httpbin/templates/index.html

@@ -56,7 +56,9 @@
 
 {% include 'httpbin.1.html' %}
 
-{% include 'trackingscripts.html' %}
+{% if env.get('HTTPBIN_TRACKING', '0') == '1' %}
+    {% include 'trackingscripts.html' %}
+{% endif %}
 
 </body>
 </html>

test_httpbin.py

@@ -1,7 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
+import os
 import base64
 import unittest
+import contextlib
 import six
 import json
 from werkzeug.http import parse_dict_header
@@ -11,6 +13,24 @@ from six import BytesIO
 import httpbin
 
 
+@contextlib.contextmanager
+def _setenv(key, value):
+    """Context manager to set an environment variable temporarily."""
+    old_value = os.environ.get(key, None)
+    if value is None:
+        os.environ.pop(key, None)
+    else:
+        os.environ[key] = value
+
+    yield
+
+    if old_value is None:
+        os.environ.pop(key, None)
+    else:
+        os.environ[key] = value
+
+
+
 def _string_to_base64(string):
     """Encodes string to utf-8 and then base64"""
     utf8_encoded = string.encode('utf-8')
@@ -419,5 +439,20 @@ class HttpbinTestCase(unittest.TestCase):
         )
         self.assertEqual(response.status_code, 416)
 
+    def test_tracking_disabled(self):
+        with _setenv('HTTPBIN_TRACKING', None):
+            response = self.app.get('/')
+        data = response.data.decode('utf-8')
+        self.assertNotIn('google-analytics', data)
+        self.assertNotIn('perfectaudience', data)
+
+    def test_tracking_enabled(self):
+        with _setenv('HTTPBIN_TRACKING', '1'):
+            response = self.app.get('/')
+        data = response.data.decode('utf-8')
+        self.assertIn('google-analytics', data)
+        self.assertIn('perfectaudience', data)
+
+
 if __name__ == '__main__':
     unittest.main()