static root file server support configurable URL and strip prefix

config.go

 )
 
 type configuration struct {
-	Host    string
-	Port    string
-	DocRoot string
+	Host        string
+	Port        string
+	DocRoot     string
+	StaticUrl   string
+	StripPrefix string
 }
 
 var configFile = "config.json"

config.json

 {
   "Host":"127.0.0.1",
   "Port":"8080",
-  "DocRoot": "./html/"
+  "DocRoot": "./html/",
+  "StaticUrl": "/",
+  "StripPrefix" : "/"
 }

main.go

 func setupRootFileServer() {
 
 	fs := http.FileServer(http.Dir(config.DocRoot))
-	http.Handle("/", http.StripPrefix("/", fs))
+	http.Handle(config.StaticUrl, http.StripPrefix(config.StripPrefix, fs))
 
 }