enhance(backend): allow disabling HTTP port completely

Signed-off-by: Yumechi <yume@yumechi.jp>

Author: eternal-flame-AD

config.example.yml

@@ -4,7 +4,7 @@
 server:
   keepaliveperiodseconds: 0 # 0 = use Go default (15s); -1 = disable keepalive; set the interval in which keepalive packets will be sent. Only change this value if you know what you are doing.
   listenaddr: "" # the address to bind on, leave empty to bind on all addresses. Prefix with "unix:" to create a unix socket. Example: "unix:/tmp/gotify.sock".
-  port: 80 # the port the HTTP server will listen on
+  port: 80 # the port the HTTP server will listen on, use -1 to disable the HTTP server
 
   ssl:
     enabled: false # if https should be enabled

runner/runner.go

@@ -22,13 +22,23 @@ func Run(router http.Handler, conf *config.Configuration) error {
 	shutdown := make(chan error)
 	go doShutdownOnSignal(shutdown)
 
-	httpListener, err := startListening("plain connection", conf.Server.ListenAddr, conf.Server.Port, conf.Server.KeepAlivePeriodSeconds)
-	if err != nil {
-		return err
+	s := &http.Server{Handler: router}
+
+	hasListener := false
+
+	if conf.Server.Port >= 0 {
+		httpListener, err := startListening("plain connection", conf.Server.ListenAddr, conf.Server.Port, conf.Server.KeepAlivePeriodSeconds)
+		if err != nil {
+			return err
+		}
+		hasListener = true
+		defer httpListener.Close()
+		go func() {
+			err := s.Serve(httpListener)
+			doShutdown(shutdown, err)
+		}()
 	}
-	defer httpListener.Close()
 
-	s := &http.Server{Handler: router}
 	if conf.Server.SSL.Enabled {
 		if conf.Server.SSL.LetsEncrypt.Enabled {
 			applyLetsEncrypt(s, conf)
@@ -40,19 +50,20 @@ func Run(router http.Handler, conf *config.Configuration) error {
 		if err != nil {
 			return err
 		}
+		hasListener = true
 		defer httpsListener.Close()
 
 		go func() {
 			err := s.ServeTLS(httpsListener, conf.Server.SSL.CertFile, conf.Server.SSL.CertKey)
 			doShutdown(shutdown, err)
 		}()
 	}
-	go func() {
-		err := s.Serve(httpListener)
-		doShutdown(shutdown, err)
-	}()
 
-	err = <-shutdown
+	if !hasListener {
+		log.Fatalln("No listener started, both plain and TLS listeners are disabled")
+	}
+
+	err := <-shutdown
 	fmt.Println("Shutting down:", err)
 
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)