Merge PR #5671: CORS - Add a Flag for CORS

client/flags/flags.go

@@ -68,6 +68,7 @@ const (
 	FlagKeyringBackend     = "keyring-backend"
 	FlagPage               = "page"
 	FlagLimit              = "limit"
+	FlagUnsafeCORS         = "unsafe-cors"
 )
 
 // LineBreak can be included in a command list to provide a blank line
@@ -141,6 +142,7 @@ func RegisterRestServerFlags(cmd *cobra.Command) *cobra.Command {
 	cmd.Flags().Uint(FlagMaxOpenConnections, 1000, "The number of maximum open connections")
 	cmd.Flags().Uint(FlagRPCReadTimeout, 10, "The RPC read timeout (in seconds)")
 	cmd.Flags().Uint(FlagRPCWriteTimeout, 10, "The RPC write timeout (in seconds)")
+	cmd.Flags().Bool(FlagUnsafeCORS, false, "Allows CORS requests from all domains. For development purposes only, use it at your own risk.")
 
 	return cmd
 }

client/lcd/root.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/gorilla/handlers"
 	"github.com/gorilla/mux"
 	"github.com/rakyll/statik/fs"
 	"github.com/spf13/cobra"
@@ -46,7 +47,7 @@ func NewRestServer(cdc *codec.Codec) *RestServer {
 }
 
 // Start starts the rest server
-func (rs *RestServer) Start(listenAddr string, maxOpen int, readTimeout, writeTimeout uint) (err error) {
+func (rs *RestServer) Start(listenAddr string, maxOpen int, readTimeout, writeTimeout uint, cors bool) (err error) {
 	server.TrapSignal(func() {
 		err := rs.listener.Close()
 		rs.log.Error("error closing listener", "err", err)
@@ -68,6 +69,11 @@ func (rs *RestServer) Start(listenAddr string, maxOpen int, readTimeout, writeTi
 		),
 	)
 
+	var h http.Handler = rs.Mux
+	if cors {
+		return rpcserver.StartHTTPServer(rs.listener, handlers.CORS()(h), rs.log, cfg)
+	}
+
 	return rpcserver.StartHTTPServer(rs.listener, rs.Mux, rs.log, cfg)
 }
 
@@ -90,6 +96,7 @@ func ServeCommand(cdc *codec.Codec, registerRoutesFn func(*RestServer)) *cobra.C
 				viper.GetInt(flags.FlagMaxOpenConnections),
 				uint(viper.GetInt(flags.FlagRPCReadTimeout)),
 				uint(viper.GetInt(flags.FlagRPCWriteTimeout)),
+				viper.GetBool(flags.FlagUnsafeCORS),
 			)
 
 			return err