Support HTTP response status code prometheus metrics (#14710)

python/sglang/srt/entrypoints/http_server.py

@@ -122,6 +122,7 @@ from sglang.srt.server_args import PortArgs, ServerArgs
 from sglang.srt.utils import (
     add_api_key_middleware,
     add_prometheus_middleware,
+    add_prometheus_track_response_middleware,
     delete_directory,
     get_bool_env_var,
     kill_process_tree,
@@ -1397,6 +1398,9 @@ def launch_server(
         )
     )
 
+    if server_args.enable_metrics:
+        add_prometheus_track_response_middleware(app)
+
     # Pass additional arguments to the lifespan function.
     # They will be used for additional initialization setups.
     if server_args.tokenizer_worker_num == 1: