indexer: Fix startup errors

- The block locator was being initialized with a zero hash, which caused `Update` return `nil` and crash the process.
- Adds an L2 conf depth parameter, since L2 can now reorg.

.changeset/slimy-files-suffer.md

+---
+'@eth-optimism/indexer': minor
+---
+
+Fix startup issues, add L2 conf depth

indexer/config.go

@@ -65,9 +65,13 @@ type Config struct {
 	// L1StartBlockNumber is the block number to start indexing L1 from.
 	L1StartBlockNumber uint64
 
-	// ConfDepth is the number of confirmations after which headers are
-	// considered confirmed.
-	ConfDepth uint64
+	// L1ConfDepth is the number of confirmations after which headers are
+	// considered confirmed on L1.
+	L1ConfDepth uint64
+
+	// L2ConfDepth is the number of confirmations after which headers are
+	// considered confirmed on L2.
+	L2ConfDepth uint64
 
 	// MaxHeaderBatchSize is the maximum number of headers to request as a
 	// batch.
@@ -122,7 +126,8 @@ func NewConfig(ctx *cli.Context) (Config, error) {
 		LogLevel:                       ctx.GlobalString(flags.LogLevelFlag.Name),
 		LogTerminal:                    ctx.GlobalBool(flags.LogTerminalFlag.Name),
 		L1StartBlockNumber:             ctx.GlobalUint64(flags.L1StartBlockNumberFlag.Name),
-		ConfDepth:                      ctx.GlobalUint64(flags.ConfDepthFlag.Name),
+		L1ConfDepth:                    ctx.GlobalUint64(flags.L1ConfDepthFlag.Name),
+		L2ConfDepth:                    ctx.GlobalUint64(flags.L2ConfDepthFlag.Name),
 		MaxHeaderBatchSize:             ctx.GlobalUint64(flags.MaxHeaderBatchSizeFlag.Name),
 		MetricsServerEnable:            ctx.GlobalBool(flags.MetricsServerEnableFlag.Name),
 		RESTHostname:                   ctx.GlobalString(flags.RESTHostnameFlag.Name),

indexer/flags/flags.go

@@ -137,11 +137,17 @@ var (
 		Value:  0,
 		EnvVar: prefixEnvVar("START_BLOCK_NUMBER"),
 	}
-	ConfDepthFlag = cli.Uint64Flag{
-		Name:   "conf-depth",
-		Usage:  "The number of confirmations after which headers are considered confirmed",
+	L1ConfDepthFlag = cli.Uint64Flag{
+		Name:   "l1-conf-depth",
+		Usage:  "The number of confirmations after which headers are considered confirmed on L1",
 		Value:  20,
-		EnvVar: prefixEnvVar("CONF_DEPTH"),
+		EnvVar: prefixEnvVar("L1_CONF_DEPTH"),
+	}
+	L2ConfDepthFlag = cli.Uint64Flag{
+		Name:   "l2-conf-depth",
+		Usage:  "The number of confirmations after which headers are considered confirmed on L1",
+		Value:  24,
+		EnvVar: prefixEnvVar("L2_CONF_DEPTH"),
 	}
 	MaxHeaderBatchSizeFlag = cli.Uint64Flag{
 		Name:   "max-header-batch-size",
@@ -203,7 +209,8 @@ var optionalFlags = []cli.Flag{
 	SentryEnableFlag,
 	SentryDsnFlag,
 	SentryTraceRateFlag,
-	ConfDepthFlag,
+	L1ConfDepthFlag,
+	L2ConfDepthFlag,
 	MaxHeaderBatchSizeFlag,
 	L1StartBlockNumberFlag,
 	RESTHostnameFlag,

indexer/indexer.go

@@ -164,7 +164,7 @@ func NewIndexer(cfg Config) (*Indexer, error) {
 		ChainID:            new(big.Int).SetUint64(cfg.ChainID),
 		AddressManager:     addrManager,
 		DB:                 db,
-		ConfDepth:          cfg.ConfDepth,
+		ConfDepth:          cfg.L1ConfDepth,
 		MaxHeaderBatchSize: cfg.MaxHeaderBatchSize,
 		StartBlockNumber:   cfg.L1StartBlockNumber,
 		Bedrock:            cfg.Bedrock,
@@ -179,7 +179,7 @@ func NewIndexer(cfg Config) (*Indexer, error) {
 		L2RPC:              l2RPC,
 		L2Client:           l2Client,
 		DB:                 db,
-		ConfDepth:          cfg.ConfDepth,
+		ConfDepth:          cfg.L2ConfDepth,
 		MaxHeaderBatchSize: cfg.MaxHeaderBatchSize,
 		StartBlockNumber:   uint64(0),
 		Bedrock:            cfg.Bedrock,

indexer/integration_tests/bedrock_test.go

@@ -73,7 +73,8 @@ func TestBedrockIndexer(t *testing.T) {
 		LogLevel:                       "info",
 		LogTerminal:                    true,
 		L1StartBlockNumber:             0,
-		ConfDepth:                      1,
+		L1ConfDepth:                    1,
+		L2ConfDepth:                    1,
 		MaxHeaderBatchSize:             2,
 		RESTHostname:                   "127.0.0.1",
 		RESTPort:                       7980,

indexer/services/l1/service.go

@@ -71,6 +71,7 @@ type Service struct {
 	batchScanner   *scc.StateCommitmentChainFilterer
 	latestHeader   uint64
 	headerSelector *ConfirmedHeaderSelector
+	l1Client       *ethclient.Client
 
 	metrics    *metrics.Metrics
 	tokenCache map[common.Address]*db.Token
@@ -143,6 +144,7 @@ func NewService(cfg ServiceConfig) (*Service, error) {
 			ZeroAddress: db.ETHL1Token,
 		},
 		isBedrock: cfg.Bedrock,
+		l1Client:  cfg.L1Client,
 	}
 	service.wg.Add(1)
 	return service, nil
@@ -202,16 +204,22 @@ func (s *Service) loop() {
 }
 
 func (s *Service) Update(newHeader *types.Header) error {
-	var lowest = db.BlockLocator{
-		Number: s.cfg.StartBlockNumber,
-	}
+	var lowest db.BlockLocator
 	highestConfirmed, err := s.cfg.DB.GetHighestL1Block()
 	if err != nil {
 		return err
 	}
-	if highestConfirmed != nil {
-		lowest = *highestConfirmed
+	if highestConfirmed == nil {
+		startHeader, err := s.l1Client.HeaderByNumber(s.ctx, new(big.Int).SetUint64(s.cfg.StartBlockNumber))
+		if err != nil {
+			return fmt.Errorf("error fetching header by number: %w", err)
+		}
+		highestConfirmed = &db.BlockLocator{
+			Number: s.cfg.StartBlockNumber,
+			Hash:   startHeader.Hash(),
+		}
 	}
+	lowest = *highestConfirmed
 
 	headers, err := s.headerSelector.NewHead(s.ctx, lowest.Number, newHeader, s.cfg.RawL1Client)
 	if err != nil {
@@ -260,22 +268,28 @@ func (s *Service) Update(newHeader *types.Header) error {
 			bridgeDepositsCh <- deposits
 		}(bridgeImpl)
 	}
-	go func() {
-		provenWithdrawals, err := s.portal.GetProvenWithdrawalsByBlockRange(s.ctx, startHeight, endHeight)
-		if err != nil {
-			errCh <- err
-			return
-		}
-		provenWithdrawalsCh <- provenWithdrawals
-	}()
-	go func() {
-		finalizedWithdrawals, err := s.portal.GetFinalizedWithdrawalsByBlockRange(s.ctx, startHeight, endHeight)
-		if err != nil {
-			errCh <- err
-			return
-		}
-		finalizedWithdrawalsCh <- finalizedWithdrawals
-	}()
+
+	if s.isBedrock {
+		go func() {
+			provenWithdrawals, err := s.portal.GetProvenWithdrawalsByBlockRange(s.ctx, startHeight, endHeight)
+			if err != nil {
+				errCh <- err
+				return
+			}
+			provenWithdrawalsCh <- provenWithdrawals
+		}()
+		go func() {
+			finalizedWithdrawals, err := s.portal.GetFinalizedWithdrawalsByBlockRange(s.ctx, startHeight, endHeight)
+			if err != nil {
+				errCh <- err
+				return
+			}
+			finalizedWithdrawalsCh <- finalizedWithdrawals
+		}()
+	} else {
+		provenWithdrawalsCh <- make(bridge.ProvenWithdrawalsMap)
+		finalizedWithdrawalsCh <- make(bridge.FinalizedWithdrawalsMap)
+	}
 
 	var receives int
 	for {