server: set SERVER header on all requests (even SIO ones), display version on startup

main.go

@@ -12,6 +12,10 @@ import (
 	"github.com/googollee/go-socket.io"
 )
 
+const (
+	VERSION = `nmdc-webfrontend/1.1.2`
+)
+
 type App struct {
 	cfg *Config
 }
@@ -224,6 +228,9 @@ func (this *App) StaticRequestHandler(w http.ResponseWriter, r *http.Request) {
 
 func (this *App) RunServer() {
 
+	// Inner mux {{
+	innerMux := http.NewServeMux()
+
 	// Socket.io handler
 	server, err := socketio.NewServer(nil)
 	if err != nil {
@@ -233,27 +240,39 @@ func (this *App) RunServer() {
 	server.On("error", func(so socketio.Socket, err error) {
 		log.Println("error:", err)
 	})
-	http.Handle("/socket.io/", server)
+	innerMux.Handle("/socket.io/", server)
 
+	// Custom favicon handler
 	if this.cfg.Web.CustomFavicon {
-		http.HandleFunc("/favicon.ico", this.customFaviconHandler)
+		innerMux.HandleFunc("/favicon.ico", this.customFaviconHandler)
 	}
 
-	// Other files: asset handler
+	// Asset handler
 	if this.cfg.Web.ExternalWebroot {
-		http.Handle("/", http.FileServer(http.Dir("client")))
+		innerMux.Handle("/", http.FileServer(http.Dir("client")))
 	} else {
-		http.HandleFunc("/", this.StaticRequestHandler)
+		innerMux.HandleFunc("/", this.StaticRequestHandler)
 	}
+	// }}
+
+	// Wrapper mux {{
+	outerMux := http.NewServeMux()
+	outerMux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Server", VERSION)
+		innerMux.ServeHTTP(w, r)
+	})
+	// }}
 
 	// Listen and serve
 	bindAddr := fmt.Sprintf("%s:%d", this.cfg.Web.BindTo, this.cfg.Web.Port)
 	log.Printf("Serving at %s...", bindAddr)
-	log.Fatal(http.ListenAndServe(bindAddr, nil))
+	log.Fatal(http.ListenAndServe(bindAddr, outerMux))
 }
 
 func main() {
 
+	log.Println(VERSION)
+
 	a, err := NewApp("nmdc-webfrontend.conf")
 	if err != nil {
 		log.Fatal(err.Error())