Add readonly mode (#1355)

* Add readonly mode in l2geth

* Remove fmt

l2geth/cmd/geth/main.go

@@ -162,6 +162,7 @@ var (
 		utils.RollupMaxCalldataSizeFlag,
 		utils.RollupBackendFlag,
 		utils.RollupEnforceFeesFlag,
+		utils.RollupReadOnlyFlag,
 		utils.RollupFeeThresholdDownFlag,
 		utils.RollupFeeThresholdUpFlag,
 		utils.SequencerClientHttpFlag,

l2geth/cmd/geth/usage.go

@@ -78,6 +78,7 @@ var AppHelpFlagGroups = []flagGroup{
 			utils.RollupFeeThresholdDownFlag,
 			utils.RollupFeeThresholdUpFlag,
 			utils.SequencerClientHttpFlag,
+			utils.RollupReadOnlyFlag,
 		},
 	},
 	{

l2geth/cmd/utils/flags.go

@@ -870,6 +870,11 @@ var (
 		Usage:  "HTTP endpoint for the sequencer client",
 		EnvVar: "SEQUENCER_CLIENT_HTTP",
 	}
+	RollupReadOnlyFlag = cli.BoolFlag{
+		Name:   "rollup.readonly",
+		Usage:  "Enable read only mode",
+		EnvVar: "ROLLUP_READONLY",
+	}
 )
 
 // MakeDataDir retrieves the currently requested data directory, terminating
@@ -1149,6 +1154,9 @@ func setRollup(ctx *cli.Context, cfg *rollup.Config) {
 	if ctx.GlobalIsSet(SequencerClientHttpFlag.Name) {
 		cfg.SequencerClientHttp = ctx.GlobalString(SequencerClientHttpFlag.Name)
 	}
+	if ctx.GlobalIsSet(RollupReadOnlyFlag.Name) {
+		cfg.IsReadOnly = ctx.GlobalBool(RollupReadOnlyFlag.Name)
+	}
 }
 
 // setLes configures the les server and ultra light client settings from the command line flags.

l2geth/eth/api_backend.go

@@ -48,6 +48,7 @@ type EthAPIBackend struct {
 	gpo             *gasprice.Oracle
 	rollupGpo       *gasprice.RollupOracle
 	verifier        bool
+	readOnly        bool
 	gasLimit        uint64
 	UsingOVM        bool
 	MaxCallDataSize int
@@ -57,6 +58,10 @@ func (b *EthAPIBackend) IsVerifier() bool {
 	return b.verifier
 }
 
+func (b *EthAPIBackend) IsReadOnly() bool {
+	return b.readOnly
+}
+
 func (b *EthAPIBackend) IsSyncing() bool {
 	return b.eth.syncService.IsSyncing()
 }

l2geth/eth/backend.go

@@ -224,7 +224,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 	eth.miner.SetExtra(makeExtraData(config.Miner.ExtraData))
 
 	log.Info("Backend Config", "max-calldata-size", config.Rollup.MaxCallDataSize, "gas-limit", config.Rollup.GasLimit, "is-verifier", config.Rollup.IsVerifier, "using-ovm", rcfg.UsingOVM)
-	eth.APIBackend = &EthAPIBackend{ctx.ExtRPCEnabled(), eth, nil, nil, config.Rollup.IsVerifier, config.Rollup.GasLimit, rcfg.UsingOVM, config.Rollup.MaxCallDataSize}
+	eth.APIBackend = &EthAPIBackend{ctx.ExtRPCEnabled(), eth, nil, nil, config.Rollup.IsVerifier, config.Rollup.IsReadOnly, config.Rollup.GasLimit, rcfg.UsingOVM, config.Rollup.MaxCallDataSize}
 	gpoParams := config.GPO
 	if gpoParams.Default == nil {
 		gpoParams.Default = config.Miner.GasPrice

l2geth/internal/ethapi/api.go

@@ -646,10 +646,10 @@ func (s *PublicBlockChainAPI) GetHeaderByHash(ctx context.Context, hash common.H
 }
 
 // GetBlockByNumber returns the requested canonical block.
-// * When blockNr is -1 the chain head is returned.
-// * When blockNr is -2 the pending chain head is returned.
-// * When fullTx is true all transactions in the block are returned, otherwise
-//   only the transaction hash is returned.
+//   - When blockNr is -1 the chain head is returned.
+//   - When blockNr is -2 the pending chain head is returned.
+//   - When fullTx is true all transactions in the block are returned, otherwise
+//     only the transaction hash is returned.
 func (s *PublicBlockChainAPI) GetBlockByNumber(ctx context.Context, number rpc.BlockNumber, fullTx bool) (map[string]interface{}, error) {
 	block, err := s.b.BlockByNumber(ctx, number)
 	if block != nil && err == nil {
@@ -1765,6 +1765,9 @@ func (s *PublicTransactionPoolAPI) SendRawTransaction(ctx context.Context, encod
 	}
 
 	if s.b.IsVerifier() {
+		if s.b.IsReadOnly() {
+			return common.Hash{}, errors.New("Cannot send raw transaction in read-only mode")
+		}
 		sequencerURL := s.b.SequencerClientHttp()
 		if sequencerURL == "" {
 			return common.Hash{}, errNoSequencerURL

l2geth/internal/ethapi/backend.go

@@ -87,6 +87,7 @@ type Backend interface {
 
 	// Optimism-specific API
 	IsVerifier() bool
+	IsReadOnly() bool
 	IsSyncing() bool
 	GetEthContext() (uint64, uint64)
 	GetRollupContext() (uint64, uint64, uint64)

l2geth/les/api_backend.go

@@ -49,6 +49,10 @@ func (b *LesApiBackend) IsVerifier() bool {
 	return false
 }
 
+func (b *LesApiBackend) IsReadOnly() bool {
+	return false
+}
+
 func (b *LesApiBackend) GasLimit() uint64 {
 	panic("not implemented")
 }

l2geth/rollup/config.go

@@ -39,4 +39,6 @@ type Config struct {
 	FeeThresholdUp   *big.Float
 	// HTTP endpoint of the sequencer
 	SequencerClientHttp string
+	// Only server the data reading requests
+	IsReadOnly bool
 }

l2geth/rollup/sync_service.go

@@ -45,6 +45,7 @@ type SyncService struct {
 	ctx                            context.Context
 	cancel                         context.CancelFunc
 	verifier                       bool
+	readOnly                       bool
 	db                             ethdb.Database
 	scope                          event.SubscriptionScope
 	txFeed                         event.Feed
@@ -127,6 +128,7 @@ func NewSyncService(ctx context.Context, cfg Config, txpool *core.TxPool, bc *co
 		ctx:                            ctx,
 		cancel:                         cancel,
 		verifier:                       cfg.IsVerifier,
+		readOnly:                       cfg.IsReadOnly,
 		enable:                         cfg.Eth1SyncServiceEnable,
 		syncing:                        atomic.Value{},
 		bc:                             bc,
@@ -157,7 +159,7 @@ func NewSyncService(ctx context.Context, cfg Config, txpool *core.TxPool, bc *co
 	// a remote server that indexes the layer one contracts. Place this
 	// code behind this if statement so that this can run without the
 	// requirement of the remote server being up.
-	if service.enable {
+	if service.enable && !cfg.IsReadOnly {
 		// Ensure that the rollup client can connect to a remote server
 		// before starting. Retry until it can connect.
 		tEnsure := time.NewTicker(10 * time.Second)
@@ -238,6 +240,12 @@ func (s *SyncService) Start() error {
 		log.Info("Running without syncing enabled")
 		return nil
 	}
+
+	if s.readOnly {
+		log.Info("Running in read only mode")
+		return nil
+	}
+
 	log.Info("Initializing Sync Service")
 	if err := s.updateGasPriceOracleCache(nil); err != nil {
 		return err
@@ -598,8 +606,8 @@ func (s *SyncService) GasPriceOracleOwnerAddress() *common.Address {
 	return &s.gasPriceOracleOwnerAddress
 }
 
-/// Update the execution context's timestamp and blocknumber
-/// over time. This is only necessary for the sequencer.
+// / Update the execution context's timestamp and blocknumber
+// / over time. This is only necessary for the sequencer.
 func (s *SyncService) updateL1BlockNumber() error {
 	context, err := s.client.GetLatestEthContext()
 	if err != nil {