utils: fix ethereum#16138 by checking if vhosts flag is set (ethereum…

…#16141)

* utils: fix ethereum#16138 by checking if vhosts flag is set

* utils,node: fix defaults for rpcvhosts

* node,utils: address review concerns

cmd/utils/flags.go

@@ -400,7 +400,7 @@ var (
 	RPCVirtualHostsFlag = cli.StringFlag{
 		Name:  "rpcvhosts",
 		Usage: "Comma separated list of virtual hostnames from which to accept requests (server enforced). Accepts '*' wildcard.",
-		Value: "localhost",
+		Value: strings.Join(node.DefaultConfig.HTTPVirtualHosts, ","),
 	}
 	RPCApiFlag = cli.StringFlag{
 		Name:  "rpcapi",
@@ -695,8 +695,9 @@ func setHTTP(ctx *cli.Context, cfg *node.Config) {
 	if ctx.GlobalIsSet(RPCApiFlag.Name) {
 		cfg.HTTPModules = splitAndTrim(ctx.GlobalString(RPCApiFlag.Name))
 	}
-
-	cfg.HTTPVirtualHosts = splitAndTrim(ctx.GlobalString(RPCVirtualHostsFlag.Name))
+	if ctx.GlobalIsSet(RPCVirtualHostsFlag.Name) {
+		cfg.HTTPVirtualHosts = splitAndTrim(ctx.GlobalString(RPCVirtualHostsFlag.Name))
+	}
 }
 
 // setWS creates the WebSocket RPC listener interface string from the set

node/defaults.go

@@ -35,11 +35,12 @@ const (
 
 // DefaultConfig contains reasonable default settings.
 var DefaultConfig = Config{
-	DataDir:     DefaultDataDir(),
-	HTTPPort:    DefaultHTTPPort,
-	HTTPModules: []string{"net", "web3"},
-	WSPort:      DefaultWSPort,
-	WSModules:   []string{"net", "web3"},
+	DataDir:          DefaultDataDir(),
+	HTTPPort:         DefaultHTTPPort,
+	HTTPModules:      []string{"net", "web3"},
+	HTTPVirtualHosts: []string{"localhost"},
+	WSPort:           DefaultWSPort,
+	WSModules:        []string{"net", "web3"},
 	P2P: p2p.Config{
 		ListenAddr: ":30303",
 		MaxPeers:   25,