Log if template is unreadable

cmd/echoip/main.go

@@ -34,8 +34,12 @@ func main() {
 	}
 
 	server := http.New(r)
-	server.Template = opts.Template
 	server.IPHeaders = opts.IPHeaders
+	if _, err := os.Stat(opts.Template); err == nil {
+		server.Template = opts.Template
+	} else {
+		log.Printf("Not configuring default handler: Template not found: %s", opts.Template)
+	}
 	if opts.ReverseLookup {
 		log.Println("Enabling reverse lookup")
 		server.LookupAddr = iputil.LookupAddr

http/http.go

@@ -308,7 +308,9 @@ func (s *Server) Handler() http.Handler {
 	}
 
 	// Browser
-	r.Route("GET", "/", s.DefaultHandler)
+	if s.Template != "" {
+		r.Route("GET", "/", s.DefaultHandler)
+	}
 
 	// Port testing
 	if s.LookupPort != nil {