Merge pull request #8235 from ethereum-optimism/challenger-lifecycle

op-challenger: cleanup service lifecycle, improve subscription ctx usage

op-batcher/batcher/service.go

@@ -312,6 +312,10 @@ func (bs *BatcherService) Stop(ctx context.Context) error {
 			result = errors.Join(result, fmt.Errorf("failed to close balance metricer: %w", err))
 		}
 	}
+	if bs.TxManager != nil {
+		bs.TxManager.Close()
+	}
+
 	if bs.metricsSrv != nil {
 		if err := bs.metricsSrv.Stop(ctx); err != nil {
 			result = errors.Join(result, fmt.Errorf("failed to stop metrics server: %w", err))

op-challenger/challenger.go

@@ -2,22 +2,19 @@ package op_challenger
 
 import (
 	"context"
-	"fmt"
+
+	"github.com/ethereum/go-ethereum/log"
 
 	"github.com/ethereum-optimism/optimism/op-challenger/config"
 	"github.com/ethereum-optimism/optimism/op-challenger/game"
-	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum-optimism/optimism/op-service/cliapp"
 )
 
-// Main is the programmatic entry-point for running op-challenger
-func Main(ctx context.Context, logger log.Logger, cfg *config.Config) error {
+// Main is the programmatic entry-point for running op-challenger with a given configuration.
+func Main(ctx context.Context, logger log.Logger, cfg *config.Config) (cliapp.Lifecycle, error) {
 	if err := cfg.Check(); err != nil {
-		return err
+		return nil, err
 	}
-	service, err := game.NewService(ctx, logger, cfg)
-	if err != nil {
-		return fmt.Errorf("failed to create the fault service: %w", err)
-	}
-
-	return service.MonitorGame(ctx)
+	srv, err := game.NewService(ctx, logger, cfg)
+	return srv, err
 }

op-challenger/challenger_test.go

@@ -12,6 +12,7 @@ import (
 
 func TestMainShouldReturnErrorWhenConfigInvalid(t *testing.T) {
 	cfg := &config.Config{}
-	err := Main(context.Background(), testlog.Logger(t, log.LvlInfo), cfg)
+	app, err := Main(context.Background(), testlog.Logger(t, log.LvlInfo), cfg)
 	require.ErrorIs(t, err, cfg.Check())
+	require.Nil(t, app)
 }

op-challenger/cmd/main.go

@@ -4,16 +4,18 @@ import (
 	"context"
 	"os"
 
-	op_challenger "github.com/ethereum-optimism/optimism/op-challenger"
-	opservice "github.com/ethereum-optimism/optimism/op-service"
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/urfave/cli/v2"
 
+	"github.com/ethereum/go-ethereum/log"
+
+	challenger "github.com/ethereum-optimism/optimism/op-challenger"
 	"github.com/ethereum-optimism/optimism/op-challenger/config"
 	"github.com/ethereum-optimism/optimism/op-challenger/flags"
 	"github.com/ethereum-optimism/optimism/op-challenger/version"
+	opservice "github.com/ethereum-optimism/optimism/op-service"
 	"github.com/ethereum-optimism/optimism/op-service/cliapp"
 	oplog "github.com/ethereum-optimism/optimism/op-service/log"
+	"github.com/ethereum-optimism/optimism/op-service/opio"
 )
 
 var (
@@ -26,14 +28,15 @@ var VersionWithMeta = opservice.FormatVersion(version.Version, GitCommit, GitDat
 
 func main() {
 	args := os.Args
-	if err := run(args, op_challenger.Main); err != nil {
+	ctx := opio.WithInterruptBlocker(context.Background())
+	if err := run(ctx, args, challenger.Main); err != nil {
 		log.Crit("Application failed", "err", err)
 	}
 }
 
-type ConfigAction func(ctx context.Context, log log.Logger, config *config.Config) error
+type ConfiguredLifecycle func(ctx context.Context, log log.Logger, config *config.Config) (cliapp.Lifecycle, error)
 
-func run(args []string, action ConfigAction) error {
+func run(ctx context.Context, args []string, action ConfiguredLifecycle) error {
 	oplog.SetupDefaults()
 
 	app := cli.NewApp()
@@ -42,20 +45,20 @@ func run(args []string, action ConfigAction) error {
 	app.Name = "op-challenger"
 	app.Usage = "Challenge outputs"
 	app.Description = "Ensures that on chain outputs are correct."
-	app.Action = func(ctx *cli.Context) error {
+	app.Action = cliapp.LifecycleCmd(func(ctx *cli.Context, close context.CancelCauseFunc) (cliapp.Lifecycle, error) {
 		logger, err := setupLogging(ctx)
 		if err != nil {
-			return err
+			return nil, err
 		}
 		logger.Info("Starting op-challenger", "version", VersionWithMeta)
 
 		cfg, err := flags.NewConfigFromCLI(ctx)
 		if err != nil {
-			return err
+			return nil, err
 		}
 		return action(ctx.Context, logger, cfg)
-	}
-	return app.Run(args)
+	})
+	return app.RunContext(ctx, args)
 }
 
 func setupLogging(ctx *cli.Context) (log.Logger, error) {

op-challenger/cmd/main_test.go

@@ -2,15 +2,19 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"testing"
 	"time"
 
-	"github.com/ethereum-optimism/optimism/op-challenger/config"
-	"github.com/ethereum-optimism/optimism/op-service/txmgr"
+	"github.com/stretchr/testify/require"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/log"
-	"github.com/stretchr/testify/require"
+
+	"github.com/ethereum-optimism/optimism/op-challenger/config"
+	"github.com/ethereum-optimism/optimism/op-service/cliapp"
+	"github.com/ethereum-optimism/optimism/op-service/txmgr"
 )
 
 var (
@@ -36,7 +40,7 @@ func TestLogLevel(t *testing.T) {
 	for _, lvl := range []string{"trace", "debug", "info", "error", "crit"} {
 		lvl := lvl
 		t.Run("AcceptValid_"+lvl, func(t *testing.T) {
-			logger, _, err := runWithArgs(addRequiredArgs(config.TraceTypeAlphabet, "--log.level", lvl))
+			logger, _, err := dryRunWithArgs(addRequiredArgs(config.TraceTypeAlphabet, "--log.level", lvl))
 			require.NoError(t, err)
 			require.NotNil(t, logger)
 		})
@@ -431,25 +435,29 @@ func TestCannonL2Genesis(t *testing.T) {
 }
 
 func verifyArgsInvalid(t *testing.T, messageContains string, cliArgs []string) {
-	_, _, err := runWithArgs(cliArgs)
+	_, _, err := dryRunWithArgs(cliArgs)
 	require.ErrorContains(t, err, messageContains)
 }
 
 func configForArgs(t *testing.T, cliArgs []string) config.Config {
-	_, cfg, err := runWithArgs(cliArgs)
+	_, cfg, err := dryRunWithArgs(cliArgs)
 	require.NoError(t, err)
 	return cfg
 }
 
-func runWithArgs(cliArgs []string) (log.Logger, config.Config, error) {
+func dryRunWithArgs(cliArgs []string) (log.Logger, config.Config, error) {
 	cfg := new(config.Config)
 	var logger log.Logger
 	fullArgs := append([]string{"op-challenger"}, cliArgs...)
-	err := run(fullArgs, func(ctx context.Context, log log.Logger, config *config.Config) error {
+	testErr := errors.New("dry-run")
+	err := run(context.Background(), fullArgs, func(ctx context.Context, log log.Logger, config *config.Config) (cliapp.Lifecycle, error) {
 		logger = log
 		cfg = config
-		return nil
+		return nil, testErr
 	})
+	if errors.Is(err, testErr) { // expected error
+		err = nil
+	}
 	return logger, *cfg, err
 }
 

op-challenger/game/fault/responder/responder_test.go

@@ -232,6 +232,9 @@ func (m *mockTxManager) From() common.Address {
 	return m.from
 }
 
+func (m *mockTxManager) Close() {
+}
+
 type mockContract struct {
 	calls            int
 	callFails        bool

op-challenger/game/monitor.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"sync"
 	"time"
 
 	"github.com/ethereum-optimism/optimism/op-challenger/game/scheduler"
@@ -39,6 +40,7 @@ type gameMonitor struct {
 	allowedGames     []common.Address
 	l1HeadsSub       ethereum.Subscription
 	l1Source         *headSource
+	runState         sync.Mutex
 }
 
 type MinimalSubscriber interface {
@@ -126,8 +128,10 @@ func (m *gameMonitor) onNewL1Head(ctx context.Context, sig eth.L1BlockRef) {
 	}
 }
 
-func (m *gameMonitor) resubscribeFunction(ctx context.Context) event.ResubscribeErrFunc {
-	return func(innerCtx context.Context, err error) (event.Subscription, error) {
+func (m *gameMonitor) resubscribeFunction() event.ResubscribeErrFunc {
+	// The ctx is cancelled as soon as the subscription is returned,
+	// but is only used to create the subscription, and does not affect the returned subscription.
+	return func(ctx context.Context, err error) (event.Subscription, error) {
 		if err != nil {
 			m.logger.Warn("resubscribing after failed L1 subscription", "err", err)
 		}
@@ -135,18 +139,21 @@ func (m *gameMonitor) resubscribeFunction(ctx context.Context) event.Resubscribe
 	}
 }
 
-func (m *gameMonitor) MonitorGames(ctx context.Context) error {
-	m.l1HeadsSub = event.ResubscribeErr(time.Second*10, m.resubscribeFunction(ctx))
-	for {
-		select {
-		case <-ctx.Done():
-			m.l1HeadsSub.Unsubscribe()
-			return nil
-		case err, ok := <-m.l1HeadsSub.Err():
-			if !ok {
-				return err
-			}
-			m.logger.Error("L1 subscription error", "err", err)
-		}
+func (m *gameMonitor) StartMonitoring() {
+	m.runState.Lock()
+	defer m.runState.Unlock()
+	if m.l1HeadsSub != nil {
+		return // already started
+	}
+	m.l1HeadsSub = event.ResubscribeErr(time.Second*10, m.resubscribeFunction())
+}
+
+func (m *gameMonitor) StopMonitoring() {
+	m.runState.Lock()
+	defer m.runState.Unlock()
+	if m.l1HeadsSub == nil {
+		return // already stopped
 	}
+	m.l1HeadsSub.Unsubscribe()
+	m.l1HeadsSub = nil
 }

op-challenger/game/monitor_test.go

@@ -84,8 +84,9 @@ func TestMonitorGames(t *testing.T) {
 			cancel()
 		}()
 
-		err := monitor.MonitorGames(ctx)
-		require.NoError(t, err)
+		monitor.StartMonitoring()
+		<-ctx.Done()
+		monitor.StopMonitoring()
 		require.Len(t, sched.scheduled, 1)
 		require.Equal(t, []common.Address{addr1, addr2}, sched.scheduled[0])
 	})
@@ -129,8 +130,9 @@ func TestMonitorGames(t *testing.T) {
 			cancel()
 		}()
 
-		err := monitor.MonitorGames(ctx)
-		require.NoError(t, err)
+		monitor.StartMonitoring()
+		<-ctx.Done()
+		monitor.StopMonitoring()
 		require.NotEmpty(t, sched.scheduled) // We might get more than one update scheduled.
 		require.Equal(t, []common.Address{addr1, addr2}, sched.scheduled[0])
 	})

op-challenger/metrics/metrics.go

 package metrics
 
 import (
-	"context"
+	"io"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethclient"
@@ -19,6 +19,8 @@ type Metricer interface {
 	RecordInfo(version string)
 	RecordUp()
 
+	StartBalanceMetrics(l log.Logger, client *ethclient.Client, account common.Address) io.Closer
+
 	// Record Tx metrics
 	txmetrics.TxMetricer
 
@@ -128,17 +130,11 @@ func (m *Metrics) Start(host string, port int) (*httputil.HTTPServer, error) {
 }
 
 func (m *Metrics) StartBalanceMetrics(
-	ctx context.Context,
 	l log.Logger,
 	client *ethclient.Client,
 	account common.Address,
-) {
-	// TODO(7684): util was refactored to close, but ctx is still being used by caller for shutdown
-	balanceMetric := opmetrics.LaunchBalanceMetrics(l, m.registry, m.ns, client, account)
-	go func() {
-		<-ctx.Done()
-		_ = balanceMetric.Close()
-	}()
+) io.Closer {
+	return opmetrics.LaunchBalanceMetrics(l, m.registry, m.ns, client, account)
 }
 
 // RecordInfo sets a pseudo-metric that contains versioning and

op-challenger/metrics/noop.go

 package metrics
 
 import (
+	"io"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/log"
+
 	txmetrics "github.com/ethereum-optimism/optimism/op-service/txmgr/metrics"
 )
 
@@ -8,6 +14,10 @@ type NoopMetricsImpl struct {
 	txmetrics.NoopTxMetrics
 }
 
+func (i *NoopMetricsImpl) StartBalanceMetrics(l log.Logger, client *ethclient.Client, account common.Address) io.Closer {
+	return nil
+}
+
 var NoopMetrics Metricer = new(NoopMetricsImpl)
 
 func (*NoopMetricsImpl) RecordInfo(version string) {}

op-e2e/actions/l2_proposer.go

@@ -54,6 +54,8 @@ func (f fakeTxMgr) BlockNumber(_ context.Context) (uint64, error) {
 func (f fakeTxMgr) Send(_ context.Context, _ txmgr.TxCandidate) (*types.Receipt, error) {
 	panic("unimplemented")
 }
+func (f fakeTxMgr) Close() {
+}
 
 func NewL2Proposer(t Testing, log log.Logger, cfg *ProposerCfg, l1 *ethclient.Client, rollupCl *sources.RollupClient) *L2Proposer {
 	proposerConfig := proposer.ProposerConfig{

op-e2e/e2eutils/challenger/helper.go

@@ -11,16 +11,19 @@ import (
 	"testing"
 	"time"
 
-	op_challenger "github.com/ethereum-optimism/optimism/op-challenger"
+	"github.com/stretchr/testify/require"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/log"
+
+	challenger "github.com/ethereum-optimism/optimism/op-challenger"
 	"github.com/ethereum-optimism/optimism/op-challenger/config"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/wait"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
+	"github.com/ethereum-optimism/optimism/op-service/cliapp"
 	"github.com/ethereum-optimism/optimism/op-service/testlog"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/log"
-	"github.com/stretchr/testify/require"
 )
 
 type Helper struct {
@@ -28,8 +31,7 @@ type Helper struct {
 	t       *testing.T
 	require *require.Assertions
 	dir     string
-	cancel  func()
-	errors  chan error
+	chl     cliapp.Lifecycle
 }
 
 type Option func(config2 *config.Config)
@@ -127,20 +129,16 @@ func NewChallenger(t *testing.T, ctx context.Context, l1Endpoint string, name st
 	log := testlog.Logger(t, log.LvlDebug).New("role", name)
 	log.Info("Creating challenger", "l1", l1Endpoint)
 	cfg := NewChallengerConfig(t, l1Endpoint, options...)
+	chl, err := challenger.Main(ctx, log, cfg)
+	require.NoError(t, err, "must init challenger")
+	require.NoError(t, chl.Start(ctx), "must start challenger")
 
-	errCh := make(chan error, 1)
-	ctx, cancel := context.WithCancel(ctx)
-	go func() {
-		defer close(errCh)
-		errCh <- op_challenger.Main(ctx, log, cfg)
-	}()
 	return &Helper{
 		log:     log,
 		t:       t,
 		require: require.New(t),
 		dir:     cfg.Datadir,
-		cancel:  cancel,
-		errors:  errCh,
+		chl:     chl,
 	}
 }
 
@@ -179,16 +177,9 @@ func NewChallengerConfig(t *testing.T, l1Endpoint string, options ...Option) *co
 }
 
 func (h *Helper) Close() error {
-	h.cancel()
-	select {
-	case <-time.After(1 * time.Minute):
-		return errors.New("timed out while stopping challenger")
-	case err := <-h.errors:
-		if !errors.Is(err, context.Canceled) {
-			return err
-		}
-		return nil
-	}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	return h.chl.Stop(ctx)
 }
 
 type GameAddr interface {

op-node/node/node.go

@@ -174,7 +174,7 @@ func (n *OpNode) initL1(ctx context.Context, cfg *Config) error {
 		if err != nil {
 			n.log.Warn("resubscribing after failed L1 subscription", "err", err)
 		}
-		return eth.WatchHeadChanges(n.resourcesCtx, n.l1Source, n.OnNewL1Head)
+		return eth.WatchHeadChanges(ctx, n.l1Source, n.OnNewL1Head)
 	})
 	go func() {
 		err, ok := <-n.l1HeadsSub.Err()
@@ -186,9 +186,9 @@ func (n *OpNode) initL1(ctx context.Context, cfg *Config) error {
 
 	// Poll for the safe L1 block and finalized block,
 	// which only change once per epoch at most and may be delayed.
-	n.l1SafeSub = eth.PollBlockChanges(n.resourcesCtx, n.log, n.l1Source, n.OnNewL1Safe, eth.Safe,
+	n.l1SafeSub = eth.PollBlockChanges(n.log, n.l1Source, n.OnNewL1Safe, eth.Safe,
 		cfg.L1EpochPollInterval, time.Second*10)
-	n.l1FinalizedSub = eth.PollBlockChanges(n.resourcesCtx, n.log, n.l1Source, n.OnNewL1Finalized, eth.Finalized,
+	n.l1FinalizedSub = eth.PollBlockChanges(n.log, n.l1Source, n.OnNewL1Finalized, eth.Finalized,
 		cfg.L1EpochPollInterval, time.Second*10)
 	return nil
 }
@@ -582,6 +582,14 @@ func (n *OpNode) Stop(ctx context.Context) error {
 	if n.l1HeadsSub != nil {
 		n.l1HeadsSub.Unsubscribe()
 	}
+	// stop polling for L1 safe-head changes
+	if n.l1SafeSub != nil {
+		n.l1SafeSub.Unsubscribe()
+	}
+	// stop polling for L1 finalized-head changes
+	if n.l1FinalizedSub != nil {
+		n.l1FinalizedSub.Unsubscribe()
+	}
 
 	// close L2 driver
 	if n.l2Driver != nil {

op-proposer/proposer/service.go

@@ -279,6 +279,11 @@ func (ps *ProposerService) Stop(ctx context.Context) error {
 			result = errors.Join(result, fmt.Errorf("failed to close balance metricer: %w", err))
 		}
 	}
+
+	if ps.TxManager != nil {
+		ps.TxManager.Close()
+	}
+
 	if ps.metricsSrv != nil {
 		if err := ps.metricsSrv.Stop(ctx); err != nil {
 			result = errors.Join(result, fmt.Errorf("failed to stop metrics server: %w", err))

op-service/eth/heads.go

@@ -17,7 +17,8 @@ type NewHeadSource interface {
 	SubscribeNewHead(ctx context.Context, ch chan<- *types.Header) (ethereum.Subscription, error)
 }
 
-// WatchHeadChanges wraps a new-head subscription from NewHeadSource to feed the given Tracker
+// WatchHeadChanges wraps a new-head subscription from NewHeadSource to feed the given Tracker.
+// The ctx is only used to create the subscription, and does not affect the returned subscription.
 func WatchHeadChanges(ctx context.Context, src NewHeadSource, fn HeadSignalFn) (ethereum.Subscription, error) {
 	headChanges := make(chan *types.Header, 10)
 	sub, err := src.SubscribeNewHead(ctx, headChanges)
@@ -25,22 +26,33 @@ func WatchHeadChanges(ctx context.Context, src NewHeadSource, fn HeadSignalFn) (
 		return nil, err
 	}
 	return event.NewSubscription(func(quit <-chan struct{}) error {
+		eventsCtx, eventsCancel := context.WithCancel(context.Background())
 		defer sub.Unsubscribe()
+		defer eventsCancel()
+
+		// We can handle a quit signal while fn is running, by closing the ctx.
+		go func() {
+			select {
+			case <-quit:
+				eventsCancel()
+			case <-eventsCtx.Done(): // don't wait for quit signal if we closed for other reasons.
+				return
+			}
+		}()
+
 		for {
 			select {
 			case header := <-headChanges:
-				fn(ctx, L1BlockRef{
+				fn(eventsCtx, L1BlockRef{
 					Hash:       header.Hash(),
 					Number:     header.Number.Uint64(),
 					ParentHash: header.ParentHash,
 					Time:       header.Time,
 				})
-			case err := <-sub.Err():
-				return err
-			case <-ctx.Done():
-				return ctx.Err()
-			case <-quit:
+			case <-eventsCtx.Done():
 				return nil
+			case err := <-sub.Err(): // if the underlying subscription fails, stop
+				return err
 			}
 		}
 	}), nil
@@ -53,7 +65,7 @@ type L1BlockRefsSource interface {
 // PollBlockChanges opens a polling loop to fetch the L1 block reference with the given label,
 // on provided interval and with request timeout. Results are returned with provided callback fn,
 // which may block to pause/back-pressure polling.
-func PollBlockChanges(ctx context.Context, log log.Logger, src L1BlockRefsSource, fn HeadSignalFn,
+func PollBlockChanges(log log.Logger, src L1BlockRefsSource, fn HeadSignalFn,
 	label BlockLabel, interval time.Duration, timeout time.Duration) ethereum.Subscription {
 	return event.NewSubscription(func(quit <-chan struct{}) error {
 		if interval <= 0 {
@@ -61,22 +73,32 @@ func PollBlockChanges(ctx context.Context, log log.Logger, src L1BlockRefsSource
 			<-quit
 			return nil
 		}
+		eventsCtx, eventsCancel := context.WithCancel(context.Background())
+		defer eventsCancel()
+		// We can handle a quit signal while fn is running, by closing the ctx.
+		go func() {
+			select {
+			case <-quit:
+				eventsCancel()
+			case <-eventsCtx.Done(): // don't wait for quit signal if we closed for other reasons.
+				return
+			}
+		}()
+
 		ticker := time.NewTicker(interval)
 		defer ticker.Stop()
 		for {
 			select {
 			case <-ticker.C:
-				reqCtx, reqCancel := context.WithTimeout(ctx, timeout)
+				reqCtx, reqCancel := context.WithTimeout(eventsCtx, timeout)
 				ref, err := src.L1BlockRefByLabel(reqCtx, label)
 				reqCancel()
 				if err != nil {
 					log.Warn("failed to poll L1 block", "label", label, "err", err)
 				} else {
-					fn(ctx, ref)
+					fn(eventsCtx, ref)
 				}
-			case <-ctx.Done():
-				return ctx.Err()
-			case <-quit:
+			case <-eventsCtx.Done():
 				return nil
 			}
 		}

op-service/txmgr/mocks/TxManager.go

@@ -43,6 +43,11 @@ func (_m *TxManager) BlockNumber(ctx context.Context) (uint64, error) {
 	return r0, r1
 }
 
+// Close provides a mock function with given fields:
+func (_m *TxManager) Close() {
+	_m.Called()
+}
+
 // From provides a mock function with given fields:
 func (_m *TxManager) From() common.Address {
 	ret := _m.Called()

op-service/txmgr/txmgr.go

@@ -49,6 +49,9 @@ type TxManager interface {
 
 	// BlockNumber returns the most recent block number from the underlying network.
 	BlockNumber(ctx context.Context) (uint64, error)
+
+	// Close the underlying connection
+	Close()
 }
 
 // ETHBackend is the set of methods that the transaction manager uses to resubmit gas & determine
@@ -80,6 +83,8 @@ type ETHBackend interface {
 	// EstimateGas returns an estimate of the amount of gas needed to execute the given
 	// transaction against the current pending block.
 	EstimateGas(ctx context.Context, msg ethereum.CallMsg) (uint64, error)
+	// Close the underlying eth connection
+	Close()
 }
 
 // SimpleTxManager is a implementation of TxManager that performs linear fee
@@ -131,6 +136,10 @@ func (m *SimpleTxManager) BlockNumber(ctx context.Context) (uint64, error) {
 	return m.backend.BlockNumber(ctx)
 }
 
+func (m *SimpleTxManager) Close() {
+	m.backend.Close()
+}
+
 // TxCandidate is a transaction candidate that can be submitted to ask the
 // [TxManager] to construct a transaction with gas price bounds.
 type TxCandidate struct {

op-service/txmgr/txmgr_test.go

@@ -261,6 +261,9 @@ func (b *mockBackend) TransactionReceipt(ctx context.Context, txHash common.Hash
 	}, nil
 }
 
+func (b *mockBackend) Close() {
+}
+
 // TestTxMgrConfirmAtMinGasPrice asserts that Send returns the min gas price tx
 // if the tx is mined instantly.
 func TestTxMgrConfirmAtMinGasPrice(t *testing.T) {
@@ -755,6 +758,9 @@ func (b *failingBackend) ChainID(ctx context.Context) (*big.Int, error) {
 	return nil, errors.New("unimplemented")
 }
 
+func (b *failingBackend) Close() {
+}
+
 // TestWaitMinedReturnsReceiptAfterFailure asserts that WaitMined is able to
 // recover from failed calls to the backend. It uses the failedBackend to
 // simulate an rpc call failure, followed by the successful return of a receipt.