feat: support request header X-Guploader-No-308 (googleapis#403)

Fixes googleapis#402

This adds support for X-GUploader-No-308: yes - if included in resumable upload request headers, instead of returning 308: resume incomplete, return 200 to satisfy the client and add a X-HTTP-Status-Code-Override: 308 response header

gcs/upload.py

@@ -241,9 +241,13 @@ def init_write_object_grpc(cls, db, request_iterator, context):
             upload.metadata.metadata["x_emulator_no_md5"] = "true"
         return upload, is_resumable
 
-    def resumable_status_rest(self):
+    def resumable_status_rest(self, override_308=False):
         response = flask.make_response()
         if len(self.media) > 1 and not self.complete:
             response.headers["Range"] = "bytes=0-%d" % (len(self.media) - 1)
         response.status_code = 308
+
+        if override_308:
+            response.headers["X-Http-Status-Code-Override"] = "308"
+            response.status_code = 200
         return response

testbench/rest_server.py

@@ -1052,7 +1052,11 @@ def resumable_upload_chunk(bucket_name):
             blob.rest_metadata(), projection, fields
         )
     else:
-        return upload.resumable_status_rest()
+        # If request header "X-GUploader-No-308: yes" is included, instead of returning 308
+        # Resume Incomplete, return 200 with a response header X-HTTP-Status-Code-Override: 308
+        # See more at https://g3doc.corp.google.com/cloud/storage/g3doc/user/scotty/faq.md?cl=head
+        override_308 = request.headers.get("X-Guploader-No-308") == "yes"
+        return upload.resumable_status_rest(override_308=override_308)
 
 
 @upload.route("/b/<bucket_name>/o", methods=["DELETE"])

tests/test_testbench_object_upload.py

@@ -167,6 +167,16 @@ def test_upload_resumable_upload_crud(self):
         self.assertEqual(response.status_code, 308)
         self.assertIn("range", response.headers)
 
+        # Test 200 overrides 308 with request header X-Guploader-No-308
+        response = self.client.put(
+            "/upload/storage/v1/b/bucket-name/o",
+            query_string={"upload_id": upload_id},
+            headers={
+                "X-Guploader-No-308": "yes",
+            },
+        )
+        self.assertEqual(response.status_code, 200)
+
         response = self.client.delete(
             "/upload/storage/v1/b/bucket-name/o",
             query_string={"upload_id": upload_id},

tests/test_upload.py

@@ -264,6 +264,11 @@ def test_resumable_rest(self):
             self.assertEqual(status.status_code, 308)
             self.assertIn("Range", status.headers)
             self.assertEqual("bytes=0-42", status.headers.get("Range", None))
+            # Simulate a chunk upload that requests 200 status code instead of 308
+            upload.media = "How vexingly quick daft zebras jump"
+            status = upload.resumable_status_rest(override_308=True)
+            self.assertEqual(status.status_code, 200)
+            self.assertIn("X-Http-Status-Code-Override", status.headers)
 
     def test_init_object_write_grpc_non_resumable(self):
         line = b"The quick brown fox jumps over the lazy dog\n"