feat: support Django asgi middleware (#625)

google/cloud/logging_v2/handlers/middleware/request.py

@@ -33,23 +33,20 @@ def _get_django_request():
     return getattr(_thread_locals, "request", None)
 
 
-try:
-    from django.utils.deprecation import MiddlewareMixin
-except ImportError:  # pragma: NO COVER
-    MiddlewareMixin = object
-
-
-class RequestMiddleware(MiddlewareMixin):
+def RequestMiddleware(get_response):
     """Saves the request in thread local"""
 
-    def __init__(self, get_response):
-        self.get_response = get_response
-
-    def process_request(self, request):
+    def middleware(request):
         """Called on each request, before Django decides which view to execute.
 
         Args:
             request(django.http.request.HttpRequest):
                 Django http request.
         """
         _thread_locals.request = request
+        if get_response:
+            return get_response(request)
+        else:
+            return None
+
+    return middleware

tests/unit/handlers/middleware/test_request.py

@@ -46,26 +46,29 @@ def _make_one(self, *args, **kw):
 
         return self._get_target_class()(*args, **kw)
 
+    def _mock_get_response(self, req):
+        return req
+
     def test_process_request(self):
         from django.test import RequestFactory
         from google.cloud.logging_v2.handlers.middleware import request
 
         middleware = self._make_one()
         mock_request = RequestFactory().get("/")
-        middleware.process_request(mock_request)
+        middleware(mock_request)
 
         django_request = request._get_django_request()
         self.assertEqual(django_request, mock_request)
 
     def test_can_instantiate_middleware_without_kwargs(self):
-        handler = mock.Mock()
-        middleware = self._make_one(handler)
-        self.assertEqual(middleware.get_response, handler)
+        middleware = self._make_one(self._mock_get_response)
+        mock_request = "test_req"
+        self.assertEqual(middleware(mock_request), mock_request)
 
     def test_can_instantiate_middleware_with_kwargs(self):
-        handler = mock.Mock()
-        middleware = self._make_one(get_response=handler)
-        self.assertEqual(middleware.get_response, handler)
+        middleware = self._make_one(get_response=self._mock_get_response)
+        mock_request = "test_req"
+        self.assertEqual(middleware(mock_request), mock_request)
 
 
 class Test__get_django_request(DjangoBase):

tests/unit/handlers/test__helpers.py

@@ -153,7 +153,7 @@ def test_no_context_header(self):
         django_request = RequestFactory().get("/")
 
         middleware = request.RequestMiddleware(None)
-        middleware.process_request(django_request)
+        middleware(django_request)
         http_request, trace_id, span_id, sampled = self._call_fut()
 
         self.assertEqual(http_request["requestMethod"], "GET")
@@ -175,7 +175,7 @@ def test_xcloud_header(self):
         )
 
         middleware = request.RequestMiddleware(None)
-        middleware.process_request(django_request)
+        middleware(django_request)
         http_request, trace_id, span_id, sampled = self._call_fut()
 
         self.assertEqual(trace_id, expected_trace_id)
@@ -195,7 +195,7 @@ def test_traceparent_header(self):
         django_request = RequestFactory().get("/", **{django_trace_header: header})
 
         middleware = request.RequestMiddleware(None)
-        middleware.process_request(django_request)
+        middleware(django_request)
         http_request, trace_id, span_id, sampled = self._call_fut()
 
         self.assertEqual(trace_id, expected_trace_id)
@@ -222,7 +222,7 @@ def test_http_request_populated(self):
         django_request.read()
 
         middleware = request.RequestMiddleware(None)
-        middleware.process_request(django_request)
+        middleware(django_request)
         http_request, *_ = self._call_fut()
         self.assertEqual(http_request["requestMethod"], "PUT")
         self.assertEqual(http_request["requestUrl"], expected_path)
@@ -236,7 +236,7 @@ def test_http_request_sparse(self):
         expected_path = "http://testserver/123"
         django_request = RequestFactory().put(expected_path)
         middleware = request.RequestMiddleware(None)
-        middleware.process_request(django_request)
+        middleware(django_request)
         http_request, *_ = self._call_fut()
         self.assertEqual(http_request["requestMethod"], "PUT")
         self.assertEqual(http_request["requestUrl"], expected_path)