fix(vertex_ai/common_utils.py): fix handling constructed url with default vertex config

litellm/llms/vertex_ai/common_utils.py

@@ -303,11 +303,26 @@ def get_vertex_location_from_url(url: str) -> Optional[str]:
     return match.group(1) if match else None
 
 
+def replace_project_and_location_in_route(
+    requested_route: str, vertex_project: str, vertex_location: str
+) -> str:
+    """
+    Replace project and location values in the route with the provided values
+    """
+    # Replace project and location values while keeping route structure
+    modified_route = re.sub(
+        r"/projects/[^/]+/locations/[^/]+/",
+        f"/projects/{vertex_project}/locations/{vertex_location}/",
+        requested_route,
+    )
+    return modified_route
+
+
 def construct_target_url(
     base_url: str,
     requested_route: str,
-    default_vertex_location: Optional[str],
+    vertex_location: Optional[str],
-    default_vertex_project: Optional[str],
+    vertex_project: Optional[str],
 ) -> httpx.URL:
     """
     Allow user to specify their own project id / location.
@@ -321,8 +336,12 @@ def construct_target_url(
     """
     new_base_url = httpx.URL(base_url)
     if "locations" in requested_route:  # contains the target project id + location
-        updated_url = new_base_url.copy_with(path=requested_route)
+        if vertex_project and vertex_location:
-        return updated_url
+            requested_route = replace_project_and_location_in_route(
+                requested_route, vertex_project, vertex_location
+            )
+        return new_base_url.copy_with(path=requested_route)
+
     """
     - Add endpoint version (e.g. v1beta for cachedContent, v1 for rest)
     - Add default project id
@@ -333,7 +352,7 @@ def construct_target_url(
         vertex_version = "v1beta1"
 
     base_requested_route = "{}/projects/{}/locations/{}".format(
-        vertex_version, default_vertex_project, default_vertex_location
+        vertex_version, vertex_project, vertex_location
     )
 
     updated_requested_route = "/" + base_requested_route + requested_route

litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py

@@ -463,13 +463,8 @@ async def vertex_proxy_route(
         location=vertex_location,
     )
 
-    if vertex_credentials is None:
-        raise Exception(
-            f"No matching vertex credentials found, for project_id: {vertex_project}, location: {vertex_location}. No default_vertex_config set either."
-        )
-
     # Use headers from the incoming request if no vertex credentials are found
-    if vertex_credentials.vertex_project is None:
+    if vertex_credentials is None or vertex_credentials.vertex_project is None:
         headers = dict(request.headers) or {}
         verbose_proxy_logger.debug(
             "default_vertex_config  not set, incoming request headers %s", headers
@@ -518,8 +513,8 @@ async def vertex_proxy_route(
     updated_url = construct_target_url(
         base_url=base_target_url,
         requested_route=encoded_endpoint,
-        default_vertex_location=vertex_location,
+        vertex_location=vertex_location,
-        default_vertex_project=vertex_project,
+        vertex_project=vertex_project,
     )
     # base_url = httpx.URL(base_target_url)
     # updated_url = base_url.copy_with(path=encoded_endpoint)

litellm/proxy/pass_through_endpoints/passthrough_endpoint_router.py

@@ -150,19 +150,17 @@ class PassthroughEndpointRouter:
         """
         Get the vertex credentials for the given project-id, location
         """
-        default_vertex_config: Optional[VertexPassThroughCredentials] = None
-
         deployment_key = self._get_deployment_key(
             project_id=project_id,
             location=location,
         )
 
         if deployment_key is None:
-            return default_vertex_config
+            return self.default_vertex_config
         if deployment_key in self.deployment_key_to_vertex_credentials:
             return self.deployment_key_to_vertex_credentials[deployment_key]
         else:
-            return default_vertex_config
+            return self.default_vertex_config
 
     def _get_credential_name_for_provider(
         self,

tests/litellm/proxy/pass_through_endpoints/test_llm_pass_through_endpoints.py

@@ -1,6 +1,7 @@
 import json
 import os
 import sys
+import traceback
 from unittest import mock
 from unittest.mock import MagicMock, patch
 
@@ -262,3 +263,71 @@ class TestVertexAIPassThroughHandler:
                 target=f"https://{test_location}-aiplatform.googleapis.com/v1/projects/{test_project}/locations/{test_location}/publishers/google/models/gemini-1.5-flash:generateContent",
                 custom_headers={"Authorization": f"Bearer {test_token}"},
             )
+
+    @pytest.mark.asyncio
+    async def test_vertex_passthrough_with_default_credentials(self, monkeypatch):
+        """
+        Test that when no passthrough credentials are set, default credentials are used in the request
+        """
+        from litellm.proxy.pass_through_endpoints.passthrough_endpoint_router import (
+            PassthroughEndpointRouter,
+        )
+
+        # Setup default credentials
+        default_project = "default-project"
+        default_location = "us-central1"
+        default_credentials = "default-creds"
+
+        pass_through_router = PassthroughEndpointRouter()
+        pass_through_router.default_vertex_config = VertexPassThroughCredentials(
+            vertex_project=default_project,
+            vertex_location=default_location,
+            vertex_credentials=default_credentials,
+        )
+
+        monkeypatch.setattr(
+            "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.passthrough_endpoint_router",
+            pass_through_router,
+        )
+
+        # Use different project/location in request than the default
+        request_project = "non-existing-project"
+        request_location = "bad-location"
+        endpoint = f"/v1/projects/{request_project}/locations/{request_location}/publishers/google/models/gemini-1.5-flash:generateContent"
+
+        mock_request = Request(
+            scope={
+                "type": "http",
+                "method": "POST",
+                "path": endpoint,
+                "headers": {},
+            }
+        )
+        mock_response = Response()
+
+        with mock.patch(
+            "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.vertex_llm_base._ensure_access_token_async"
+        ) as mock_ensure_token, mock.patch(
+            "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.vertex_llm_base._get_token_and_url"
+        ) as mock_get_token, mock.patch(
+            "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.create_pass_through_route"
+        ) as mock_create_route:
+            mock_ensure_token.return_value = ("test-auth-header", default_project)
+            mock_get_token.return_value = (default_credentials, "")
+
+            try:
+                await vertex_proxy_route(
+                    endpoint=endpoint,
+                    request=mock_request,
+                    fastapi_response=mock_response,
+                )
+            except Exception as e:
+                traceback.print_exc()
+                print(f"Error: {e}")
+
+            # Verify default credentials were used
+            mock_create_route.assert_called_once_with(
+                endpoint=endpoint,
+                target=f"https://{default_location}-aiplatform.googleapis.com/v1/projects/{default_project}/locations/{default_location}/publishers/google/models/gemini-1.5-flash:generateContent",
+                custom_headers={"Authorization": f"Bearer {default_credentials}"},
+            )