From f5cb2ff3289b01339fcef55d20485b8812857b35 Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Fri, 18 Sep 2020 14:14:26 +0200
Subject: [PATCH] Rework synchronisation between webserver and main.

We now exit with an error code if the webserver couldn't start.
---
 sfu.go                 | 18 +++++++++++++++---
 webserver/webserver.go | 21 ++++++++++-----------
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/sfu.go b/sfu.go
index e3ec50d..7e57ab4 100644
--- a/sfu.go
+++ b/sfu.go
@@ -81,10 +81,22 @@ func main() {
 	group.IceFilename = filepath.Join(dataDir, "ice-servers.json")
 
 	go group.ReadPublicGroups()
-	webserver.Serve(httpAddr, dataDir)
+
+	serverDone := make(chan struct{})
+	go func() {
+		err := webserver.Serve(httpAddr, dataDir)
+		if err != nil {
+			log.Printf("Server: %v", err)
+		}
+		close(serverDone)
+	}()
 
 	terminate := make(chan os.Signal, 1)
 	signal.Notify(terminate, syscall.SIGINT, syscall.SIGTERM)
-	<-terminate
-	webserver.Shutdown()
+	select {
+	case <-terminate:
+		webserver.Shutdown()
+	case <-serverDone:
+		os.Exit(1)
+	}
 }
diff --git a/webserver/webserver.go b/webserver/webserver.go
index d64148b..1b90fe3 100644
--- a/webserver/webserver.go
+++ b/webserver/webserver.go
@@ -29,7 +29,7 @@ var server *http.Server
 
 var StaticRoot string
 
-func Serve(address string, dataDir string) {
+func Serve(address string, dataDir string) error {
 	http.Handle("/", &fileHandler{http.Dir(StaticRoot)})
 	http.HandleFunc("/group/", groupHandler)
 	http.HandleFunc("/recordings",
@@ -61,16 +61,15 @@ func Serve(address string, dataDir string) {
 			return true
 		})
 	})
-	go func() {
-		var err error
-		err = server.ListenAndServeTLS(
-			filepath.Join(dataDir, "cert.pem"),
-			filepath.Join(dataDir, "key.pem"),
-		)
-		if err != nil && err != http.ErrServerClosed {
-			log.Printf("ListenAndServeTLS: %v", err)
-		}
-	}()
+
+	err := server.ListenAndServeTLS(
+		filepath.Join(dataDir, "cert.pem"),
+		filepath.Join(dataDir, "key.pem"),
+	)
+	if err == http.ErrServerClosed {
+		return nil
+	}
+	return err
 }
 
 func mungeHeader(w http.ResponseWriter) {