From e16881b7c87a3666c68d668969f947ed3442cc59 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc=20Sch=C3=A4fer?= <git@marcschaeferger.de>
Date: Wed, 8 Oct 2025 01:09:18 +0200
Subject: [PATCH] fix(sonar): SetObservableCallback uses unregister stopper
 instead of empty function to satisfy S1186

---
 internal/telemetry/metrics.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/internal/telemetry/metrics.go b/internal/telemetry/metrics.go
index e29c166..c6158fe 100644
--- a/internal/telemetry/metrics.go
+++ b/internal/telemetry/metrics.go
@@ -207,10 +207,14 @@ var (
 //	})
 func SetObservableCallback(cb func(context.Context, metric.Observer) error) {
 	obsOnce.Do(func() {
-	if _, e := meter.RegisterCallback(cb, mSiteOnline, mSiteLastHeartbeat, mTunnelSessions); e != nil {
+		reg, e := meter.RegisterCallback(cb, mSiteOnline, mSiteLastHeartbeat, mTunnelSessions)
+		if e != nil {
 			otel.Handle(e)
+			obsStopper = func() {}
+			return
 		}
-		obsStopper = func() { /* no-op; otel callbacks are unregistered when provider shuts down */ }
+		// Provide a functional stopper mirroring proxy/build-info behavior
+		obsStopper = func() { _ = reg.Unregister() }
 	})
 }