From b9adb28e90f838ceda6a7dd2118c81d3a3fd3dad Mon Sep 17 00:00:00 2001
From: paspo <paolo@asperti.com>
Date: Fri, 3 Jul 2026 18:18:48 +0200
Subject: [PATCH] support use of random free port for healthcheck

---
 main.go | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/main.go b/main.go
index 9da12a1..47e0e0e 100644
--- a/main.go
+++ b/main.go
@@ -190,7 +190,15 @@ func main() {
 		})
 	clients := startSending(*maxClients, *bannerMaxLength, records)
 
-	// Start the healthcheck listener.
+	if *healthcheckPort == "0" || *healthcheckPort == "" {
+		l, err := net.Listen("tcp", *healthcheckHost+":0")
+		if err != nil {
+			glog.Fatalf("Failed to pick a free healthcheck port: %v", err)
+		}
+		actualPort := l.Addr().(*net.TCPAddr).Port
+		*healthcheckPort = strconv.Itoa(actualPort)
+		l.Close()
+	}
 	health.StartListener(*healthcheckHost, *healthcheckPort)
 
 	interval := time.Duration(*intervalMs) * time.Millisecond