REST: Add 'max-body-bytes' Flag (cosmos#6167)

* Add max-body-bytes flag for REST service

* Add changelog entries

* Change types

CHANGELOG.md

@@ -99,6 +99,7 @@ information on how to implement the new `Keyring` interface.
 
 ### Features
 
+* (rest) [\#6167](https://github.com/cosmos/cosmos-sdk/pull/6167) Support `max-body-bytes` CLI flag for the REST service.
 * (x/ibc) [\#5588](https://github.com/cosmos/cosmos-sdk/pull/5588) Add [ICS 024 - Host State Machine Requirements](https://github.com/cosmos/ics/tree/master/spec/ics-024-host-requirements) subpackage to `x/ibc` module.
 * (x/ibc) [\#5277](https://github.com/cosmos/cosmos-sdk/pull/5277) `x/ibc` changes from IBC alpha. For more details check the the  [`x/ibc/spec`](https://github.com/cosmos/tree/master/x/ibc/spec) directory:
   * [ICS 002 - Client Semantics](https://github.com/cosmos/ics/tree/master/spec/ics-002-client-semantics) subpackage

client/flags/flags.go

@@ -63,6 +63,7 @@ const (
 	FlagMaxOpenConnections = "max-open"
 	FlagRPCReadTimeout     = "read-timeout"
 	FlagRPCWriteTimeout    = "write-timeout"
+	FlagRPCMaxBodyBytes    = "max-body-bytes"
 	FlagOutputDocument     = "output-document" // inspired by wget -O
 	FlagSkipConfirmation   = "yes"
 	FlagProve              = "prove"
@@ -148,6 +149,7 @@ 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().Uint(FlagRPCMaxBodyBytes, 1000000, "The RPC max body bytes (in MB)")
 	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

@@ -46,28 +46,23 @@ func NewRestServer(cdc *codec.Codec) *RestServer {
 	}
 }
 
-// Start starts the rest server
-func (rs *RestServer) Start(listenAddr string, maxOpen int, readTimeout, writeTimeout uint, cors bool) (err error) {
+// StartWithConfig starts the REST server that listens on the provided listenAddr.
+// It will use the provided RPC configuration.
+func (rs *RestServer) StartWithConfig(listenAddr string, cors bool, cfg *rpcserver.Config) error {
 	server.TrapSignal(func() {
 		err := rs.listener.Close()
 		rs.log.Error("error closing listener", "err", err)
 	})
 
-	cfg := rpcserver.DefaultConfig()
-	cfg.MaxOpenConnections = maxOpen
-	cfg.ReadTimeout = time.Duration(readTimeout) * time.Second
-	cfg.WriteTimeout = time.Duration(writeTimeout) * time.Second
-
-	rs.listener, err = rpcserver.Listen(listenAddr, cfg)
+	listener, err := rpcserver.Listen(listenAddr, cfg)
 	if err != nil {
-		return
+		return err
 	}
 
+	rs.listener = listener
+
 	rs.log.Info(
-		fmt.Sprintf(
-			"Starting application REST service (chain-id: %q)...",
-			viper.GetString(flags.FlagChainID),
-		),
+		fmt.Sprintf("Starting application REST service (chain-id: %q)...", viper.GetString(flags.FlagChainID)),
 	)
 
 	var h http.Handler = rs.Mux
@@ -79,6 +74,18 @@ func (rs *RestServer) Start(listenAddr string, maxOpen int, readTimeout, writeTi
 	return rpcserver.StartHTTPServer(rs.listener, rs.Mux, rs.log, cfg)
 }
 
+// Start starts the REST server that listens on the provided listenAddr. The REST
+// service will use Tendermint's default RPC configuration, where the R/W timeout
+// and max open connections are overridden.
+func (rs *RestServer) Start(listenAddr string, maxOpen int, readTimeout, writeTimeout uint, cors bool) error {
+	cfg := rpcserver.DefaultConfig()
+	cfg.MaxOpenConnections = maxOpen
+	cfg.ReadTimeout = time.Duration(readTimeout) * time.Second
+	cfg.WriteTimeout = time.Duration(writeTimeout) * time.Second
+
+	return rs.StartWithConfig(listenAddr, cors, cfg)
+}
+
 // ServeCommand will start the application REST service as a blocking process. It
 // takes a codec to create a RestServer object and a function to register all
 // necessary routes.
@@ -92,16 +99,18 @@ func ServeCommand(cdc *codec.Codec, registerRoutesFn func(*RestServer)) *cobra.C
 			registerRoutesFn(rs)
 			rs.registerSwaggerUI()
 
-			// Start the rest server and return error if one exists
-			err = rs.Start(
+			cfg := rpcserver.DefaultConfig()
+			cfg.MaxOpenConnections = viper.GetInt(flags.FlagMaxOpenConnections)
+			cfg.ReadTimeout = time.Duration(viper.GetInt64(flags.FlagRPCReadTimeout)) * time.Second
+			cfg.WriteTimeout = time.Duration(viper.GetInt64(flags.FlagRPCWriteTimeout)) * time.Second
+			cfg.MaxBodyBytes = viper.GetInt64(flags.FlagRPCMaxBodyBytes)
+
+			// start the rest server and return error if one exists
+			return rs.StartWithConfig(
 				viper.GetString(flags.FlagListenAddr),
-				viper.GetInt(flags.FlagMaxOpenConnections),
-				uint(viper.GetInt(flags.FlagRPCReadTimeout)),
-				uint(viper.GetInt(flags.FlagRPCWriteTimeout)),
 				viper.GetBool(flags.FlagUnsafeCORS),
+				cfg,
 			)
-
-			return err
 		},
 	}