From 5af6e4d1ec870ec1c688cc8a89c41ebf8f5976a3 Mon Sep 17 00:00:00 2001
From: Cameron Moore <moorereason@gmail.com>
Date: Fri, 27 Dec 2019 12:01:12 -0600
Subject: [PATCH] Open listener port earlier

---
 webhook.go | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/webhook.go b/webhook.go
index 2902030..f87be2c 100644
--- a/webhook.go
+++ b/webhook.go
@@ -112,6 +112,23 @@ func main() {
 		hooksFiles = append(hooksFiles, "hooks.json")
 	}
 
+	addr := fmt.Sprintf("%s:%d", *ip, *port)
+
+	// Open listener early so we can drop privileges.
+	ln, err := net.Listen("tcp", addr)
+	if err != nil {
+		log.Printf("error listening on port: %s", err)
+		return
+	}
+
+	if *setUID != 0 {
+		err := dropPrivileges(*setUID, *setGID)
+		if err != nil {
+			log.Printf("error dropping privileges: %s", err)
+			return
+		}
+	}
+
 	if *logPath != "" {
 		file, err := os.OpenFile(*logPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
 		if err != nil {
@@ -217,29 +234,12 @@ func main() {
 
 	r.HandleFunc(hooksURL, hookHandler)
 
-	addr := fmt.Sprintf("%s:%d", *ip, *port)
-
 	// Create common HTTP server settings
 	svr := &http.Server{
 		Addr:    addr,
 		Handler: r,
 	}
 
-	// Open listener
-	ln, err := net.Listen("tcp", addr)
-	if err != nil {
-		log.Printf("error listening on port: %s", err)
-		return
-	}
-
-	if *setUID != 0 {
-		err := dropPrivileges(*setUID, *setGID)
-		if err != nil {
-			log.Printf("error dropping privileges: %s", err)
-			return
-		}
-	}
-
 	// Serve HTTP
 	if !*secure {
 		log.Printf("serving hooks on http://%s%s", addr, hooksURL)