to add health status check for remote vllm

llama_stack/providers/remote/inference/vllm/vllm.py

@@ -9,6 +9,7 @@ from collections.abc import AsyncGenerator, AsyncIterator
 from typing import Any
 
 import httpx
+import requests
 from openai import AsyncOpenAI
 from openai.types.chat.chat_completion_chunk import (
     ChatCompletionChunk as OpenAIChatCompletionChunk,
@@ -56,7 +57,11 @@ from llama_stack.apis.inference.inference import (
 from llama_stack.apis.models import Model, ModelType
 from llama_stack.models.llama.datatypes import BuiltinTool, StopReason, ToolCall
 from llama_stack.models.llama.sku_list import all_registered_models
-from llama_stack.providers.datatypes import ModelsProtocolPrivate
+from llama_stack.providers.datatypes import (
+    HealthResponse,
+    HealthStatus,
+    ModelsProtocolPrivate,
+)
 from llama_stack.providers.utils.inference.model_registry import (
     ModelRegistryHelper,
     build_hf_repo_model_entry,
@@ -298,6 +303,30 @@ class VLLMInferenceAdapter(Inference, ModelsProtocolPrivate):
     async def unregister_model(self, model_id: str) -> None:
         pass
 
+    async def health(self) -> HealthResponse:
+        """
+        Performs a health check by verifying connectivity to the remote VLLM server.
+        This method is used by initialize() and the Provider API to verify
+        that the service is running correctly.
+        Returns:
+            HealthResponse: A dictionary containing the health status.
+        """
+        try:
+            headers = {}
+            client = self._create_client() if self.client is None else self.client
+            if client.api_key:
+                headers["Authorization"] = f"Bearer {client.api_key}"
+            models_url = f"{client.base_url}/v1/models"
+            requests.get(models_url, headers=headers, timeout=10)
+            return HealthResponse(
+                status=HealthStatus.OK
+            )
+        except Exception as ex:
+            return HealthResponse(
+                status=HealthStatus.ERROR,
+                message=f"Health check failed: {str(ex)}"
+            )
+
     async def _get_model(self, model_id: str) -> Model:
         if not self.model_store:
             raise ValueError("Model store not set")