From a56fd32e0affbe9cb61abb5ee3ec0a0bd15f5bf0 Mon Sep 17 00:00:00 2001
From: tmpolaczyk <44604217+tmpolaczyk@users.noreply.github.com>
Date: Thu, 21 Sep 2023 12:22:42 +0200
Subject: [PATCH] Add graceful shutdown to prometheus server (#1637)

Fixes prometheus server not stopping if there are open connections
---
 substrate/utils/prometheus/src/lib.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/substrate/utils/prometheus/src/lib.rs b/substrate/utils/prometheus/src/lib.rs
index 581666635a..ed1f9137ae 100644
--- a/substrate/utils/prometheus/src/lib.rs
+++ b/substrate/utils/prometheus/src/lib.rs
@@ -111,10 +111,16 @@ async fn init_prometheus_with_listener(
 		}
 	});
 
-	let server = Server::builder(listener).serve(service);
+	let (signal, on_exit) = tokio::sync::oneshot::channel::<()>();
+	let server = Server::builder(listener).serve(service).with_graceful_shutdown(async {
+		let _ = on_exit.await;
+	});
 
 	let result = server.await.map_err(Into::into);
 
+	// Gracefully shutdown server, otherwise the server does not stop if it has open connections
+	let _ = signal.send(());
+
 	result
 }