UX: add vLLM env info in '/server_info' (#31899)

Signed-off-by: Jee Jee Li <pandaleefree@gmail.com>

vllm/entrypoints/serve/instrumentator/server_info.py

@@ -19,6 +19,19 @@ router = APIRouter()
 PydanticVllmConfig = pydantic.TypeAdapter(VllmConfig)
 
 
+def _get_vllm_env_vars():
+    from vllm.config.utils import normalize_value
+
+    vllm_envs = {}
+    for key in dir(envs):
+        if key.startswith("VLLM_") and "KEY" not in key:
+            value = getattr(envs, key, None)
+            if value is not None:
+                value = normalize_value(value)
+                vllm_envs[key] = value
+    return vllm_envs
+
+
 @router.get("/server_info")
 async def show_server_info(
     raw_request: Request,
@@ -26,10 +39,13 @@ async def show_server_info(
 ):
     vllm_config: VllmConfig = raw_request.app.state.vllm_config
     server_info = {
-        "vllm_config": str(vllm_config)
+        "vllm_config": (
+            str(vllm_config)
             if config_format == "text"
             else PydanticVllmConfig.dump_python(vllm_config, mode="json", fallback=str)
+        ),
         # fallback=str is needed to handle e.g. torch.dtype
+        "vllm_env": _get_vllm_env_vars(),
     }
     return JSONResponse(content=server_info)