update and use rs/dnscache implementation instead of custom (#13348)

additionally optimize for IP only setups, avoid doing
unnecessary lookups if the Dial addr is an IP.

allow support for multiple listeners on same socket,
this is mainly meant for future purposes.

cmd/server-main.go

@@ -431,8 +431,6 @@ func (lw nullWriter) Write(b []byte) (int, error) {
 
 // serverMain handler called for 'minio server' command.
 func serverMain(ctx *cli.Context) {
-	defer globalDNSCache.Stop()
-
 	signal.Notify(globalOSSignalCh, os.Interrupt, syscall.SIGTERM, syscall.SIGQUIT)
 
 	go handleSignals()
@@ -496,14 +494,15 @@ func serverMain(ctx *cli.Context) {
 		getCert = globalTLSCerts.GetCertificate
 	}
 
-	httpServer := xhttp.NewServer([]string{globalMinioAddr}, criticalErrorHandler{corsHandler(handler)}, getCert)
+	httpServer := xhttp.NewServer([]string{globalMinioAddr},
+		criticalErrorHandler{corsHandler(handler)}, getCert)
 	httpServer.BaseContext = func(listener net.Listener) context.Context {
 		return GlobalContext
 	}
 	// Turn-off random logging by Go internally
 	httpServer.ErrorLog = log.New(&nullWriter{}, "", 0)
 	go func() {
-		globalHTTPServerErrorCh <- httpServer.Start()
+		globalHTTPServerErrorCh <- httpServer.Start(GlobalContext)
 	}()
 
 	setHTTPServer(httpServer)