[Frontend] Add sagemaker_standards dynamic lora adapter and stateful session management decorators to vLLM OpenAI API server (#27892)

Signed-off-by: Zuyi Zhao <zhaozuy@amazon.com>
Signed-off-by: Shen Teng <sheteng@amazon.com>
Co-authored-by: Shen Teng <sheteng@amazon.com>
Co-authored-by: Robert Shaw <114415538+robertgshaw2-redhat@users.noreply.github.com>

vllm/entrypoints/sagemaker/__init__.py

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+"""SageMaker-specific integration for vLLM."""

vllm/entrypoints/sagemaker/routes.py

@@ -0,0 +1,72 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import json
+from http import HTTPStatus
+
+import model_hosting_container_standards.sagemaker as sagemaker_standards
+import pydantic
+from fastapi import APIRouter, Depends, HTTPException, Request
+from fastapi.responses import JSONResponse, Response
+
+from vllm.entrypoints.openai.api_server import (
+    INVOCATION_VALIDATORS,
+    base,
+    health,
+    validate_json_request,
+)
+from vllm.entrypoints.openai.protocol import ErrorResponse
+
+
+def register_sagemaker_routes(router: APIRouter):
+    @router.post("/ping", response_class=Response)
+    @router.get("/ping", response_class=Response)
+    @sagemaker_standards.register_ping_handler
+    async def ping(raw_request: Request) -> Response:
+        """Ping check. Endpoint required for SageMaker"""
+        return await health(raw_request)
+
+    @router.post(
+        "/invocations",
+        dependencies=[Depends(validate_json_request)],
+        responses={
+            HTTPStatus.BAD_REQUEST.value: {"model": ErrorResponse},
+            HTTPStatus.UNSUPPORTED_MEDIA_TYPE.value: {"model": ErrorResponse},
+            HTTPStatus.INTERNAL_SERVER_ERROR.value: {"model": ErrorResponse},
+        },
+    )
+    @sagemaker_standards.register_invocation_handler
+    @sagemaker_standards.stateful_session_manager()
+    @sagemaker_standards.inject_adapter_id(adapter_path="model")
+    async def invocations(raw_request: Request):
+        """For SageMaker, routes requests based on the request type."""
+        try:
+            body = await raw_request.json()
+        except json.JSONDecodeError as e:
+            raise HTTPException(
+                status_code=HTTPStatus.BAD_REQUEST.value,
+                detail=f"JSON decode error: {e}",
+            ) from e
+
+        valid_endpoints = [
+            (validator, endpoint)
+            for validator, (get_handler, endpoint) in INVOCATION_VALIDATORS
+            if get_handler(raw_request) is not None
+        ]
+
+        for request_validator, endpoint in valid_endpoints:
+            try:
+                request = request_validator.validate_python(body)
+            except pydantic.ValidationError:
+                continue
+
+            return await endpoint(request, raw_request)
+
+        type_names = [
+            t.__name__ if isinstance(t := validator._type, type) else str(t)
+            for validator, _ in valid_endpoints
+        ]
+        msg = f"Cannot find suitable handler for request. Expected one of: {type_names}"
+        res = base(raw_request).create_error_response(message=msg)
+        return JSONResponse(content=res.model_dump(), status_code=res.error.code)
+
+    return router