Add middleware to strip content-type headers from GETs

bigchaindb/web/server.py

@@ -13,6 +13,7 @@ import gunicorn.app.base
 from bigchaindb import utils
 from bigchaindb import Bigchain
 from bigchaindb.web.routes import add_routes
+from bigchaindb.web.strip_content_type_middleware import StripContentTypeMiddleware
 
 
 # TODO: Figure out if we do we need all this boilerplate.
@@ -60,6 +61,7 @@ def create_app(*, debug=False, threads=1):
     """
 
     app = Flask(__name__)
+    app.wsgi_app = StripContentTypeMiddleware(app.wsgi_app)
 
     CORS(app)
 

bigchaindb/web/strip_content_type_middleware.py

@@ -0,0 +1,27 @@
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class StripContentTypeMiddleware:
+    """WSGI middleware to strip Content-Type header for GETs."""
+
+    def __init__(self, app):
+        """Create the new middleware.
+
+        Args:
+            app: a flask application
+        """
+        self.app = app
+
+    def __call__(self, environ, start_response):
+        """Run the middleware and then call the original WSGI application."""
+
+        if environ['REQUEST_METHOD'] == 'GET':
+            try:
+                del environ['CONTENT_TYPE']
+            except KeyError:
+                pass
+            else:
+                logger.debug('Remove header "Content-Type" from GET request')
+        return self.app(environ, start_response)

tests/web/test_content_type_middleware.py

@@ -0,0 +1,40 @@
+from unittest.mock import Mock
+
+OUTPUTS_ENDPOINT = '/api/v1/outputs/'
+
+
+def test_middleware_does_nothing_when_no_content_type_is_provided():
+    from bigchaindb.web.strip_content_type_middleware import StripContentTypeMiddleware
+    mock = Mock()
+    middleware = StripContentTypeMiddleware(mock)
+    middleware({'REQUEST_METHOD': 'GET'}, None)
+
+    assert 'CONTENT_TYPE' not in mock.call_args[0][0]
+
+
+def test_middleware_strips_content_type_from_gets():
+    from bigchaindb.web.strip_content_type_middleware import StripContentTypeMiddleware
+    mock = Mock()
+    middleware = StripContentTypeMiddleware(mock)
+    middleware({'REQUEST_METHOD': 'GET',
+                'CONTENT_TYPE': 'application/json'},
+               None)
+
+    assert 'CONTENT_TYPE' not in mock.call_args[0][0]
+
+
+def test_middleware_does_notstrip_content_type_from_other_methods():
+    from bigchaindb.web.strip_content_type_middleware import StripContentTypeMiddleware
+    mock = Mock()
+    middleware = StripContentTypeMiddleware(mock)
+    middleware({'REQUEST_METHOD': 'POST',
+                'CONTENT_TYPE': 'application/json'},
+               None)
+
+    assert 'CONTENT_TYPE' in mock.call_args[0][0]
+
+
+def test_get_outputs_endpoint_with_content_type(client, user_pk):
+    res = client.get(OUTPUTS_ENDPOINT + '?public_key={}'.format(user_pk),
+                     headers=[('Content-Type', 'application/json')])
+    assert res.status_code == 200