[Serve] Unwrap Flask Request from ServeHandle (#10845)

python/ray/serve/tests/test_handle.py

@@ -84,6 +84,28 @@ def test_handle_http_args(serve_instance):
         resp["headers"]["X-Custom-Header"] == "value"
 
 
+def test_handle_inject_flask_request(serve_instance):
+    client = serve_instance
+
+    def echo_request_type(request):
+        return str(type(request))
+
+    client.create_backend("echo:v0", echo_request_type)
+    client.create_endpoint("echo", backend="echo:v0", route="/echo")
+
+    def wrapper_model(web_request):
+        handle = serve.connect().get_handle("echo")
+        return ray.get(handle.remote(web_request))
+
+    client.create_backend("wrapper:v0", wrapper_model)
+    client.create_endpoint("wrapper", backend="wrapper:v0", route="/wrapper")
+
+    for route in ["/echo", "/wrapper"]:
+        resp = requests.get(f"http://127.0.0.1:8000{route}")
+        request_type = resp.text
+        assert request_type == "<class 'flask.wrappers.Request'>"
+
+
 if __name__ == "__main__":
     import sys
     import pytest

python/ray/serve/utils.py

@@ -15,6 +15,7 @@ from collections import UserDict
 import requests
 import numpy as np
 import pydantic
+import flask
 
 import ray
 from ray.serve.constants import HTTP_PROXY_TIMEOUT
@@ -88,8 +89,15 @@ def parse_request_item(request_item):
         asgi_scope, body_bytes = request_item.args
         return build_flask_request(asgi_scope, io.BytesIO(body_bytes))
     else:
+        arg = request_item.args[0] if len(request_item.args) == 1 else None
+
+        # If the input data from handle is web request, we don't need to wrap
+        # it in ServeRequest.
+        if isinstance(arg, flask.Request):
+            return arg
+
         return ServeRequest(
-            request_item.args[0] if len(request_item.args) == 1 else None,
+            arg,
             request_item.kwargs,
             headers=request_item.metadata.http_headers,
             method=request_item.metadata.http_method,