Conductor and sequencer p2p refactoring (#11455)

* Shutdown sequencer before stopping p2p

* Check p2p isn't also disabled
Co-authored-by: Sebastian Stammler <seb@oplabs.co>

* Remove missed time.Sleep

* Fix up use of SetupP2P.Disabled

* Revert error check after RPC boundary

* Add comment about context for StopSequencer

* Add Config.p2pEnabled

* op-node: Make Config.P2PEnabled public

---------
Co-authored-by: Sebastian Stammler <seb@oplabs.co>

op-chain-ops/script/console2_gen.go

@@ -1511,4 +1511,3 @@ func (c *ConsolePrecompile) Log_59cfcbe3(p0 *big.Int, p1 *big.Int, p2 *big.Int,
 func (c *ConsolePrecompile) Log_193fb800(p0 *big.Int, p1 *big.Int, p2 *big.Int, p3 *big.Int) {
 	c.log(p0, p1, p2, p3)
 }
-

op-conductor/conductor/service.go

@@ -647,9 +647,12 @@ func (oc *OpConductor) action() {
 
 	oc.log.Debug("exiting action with status and error", "status", status, "err", err)
 	if err != nil {
+		select {
+		case <-oc.shutdownCtx.Done():
+		case <-time.After(oc.retryBackoff()):
 			oc.log.Error("failed to execute step, queueing another one to retry", "err", err, "status", status)
-		time.Sleep(oc.retryBackoff())
 			oc.queueAction()
+		}
 		return
 	}
 
@@ -683,18 +686,33 @@ func (oc *OpConductor) transferLeader() error {
 }
 
 func (oc *OpConductor) stopSequencer() error {
-	oc.log.Info("stopping sequencer", "server", oc.cons.ServerID(), "leader", oc.leader.Load(), "healthy", oc.healthy.Load(), "active", oc.seqActive.Load())
-
-	_, err := oc.ctrl.StopSequencer(context.Background())
-	if err != nil {
+	oc.log.Info(
+		"stopping sequencer",
+		"server", oc.cons.ServerID(),
+		"leader", oc.leader.Load(),
+		"healthy", oc.healthy.Load(),
+		"active", oc.seqActive.Load())
+
+	// Quoting (@zhwrd): StopSequencer is called after conductor loses leadership. In the event that
+	// the StopSequencer call fails, it actually has little real consequences because the sequencer
+	// cant produce a block and gossip / commit it to the raft log (requires leadership). Once
+	// conductor comes back up it will check its leader and sequencer state and attempt to stop the
+	// sequencer again. So it is "okay" to fail to stop a sequencer, the state will eventually be
+	// rectified and we won't have two active sequencers that are actually producing blocks.
+	//
+	// To that end we allow to cancel the StopSequencer call if we're shutting down.
+	latestHead, err := oc.ctrl.StopSequencer(oc.shutdownCtx)
+	if err == nil {
+		// None of the consensus state should have changed here so don't log it again.
+		oc.log.Info("stopped sequencer", "latestHead", latestHead)
+	} else {
 		if strings.Contains(err.Error(), driver.ErrSequencerAlreadyStopped.Error()) {
-			oc.log.Warn("sequencer already stopped.", "err", err)
+			oc.log.Warn("sequencer already stopped", "err", err)
 		} else {
 			return errors.Wrap(err, "failed to stop sequencer")
 		}
 	}
 	oc.metrics.RecordStopSequencer(err == nil)
-
 	oc.seqActive.Store(false)
 	return nil
 }

op-e2e/setup.go

@@ -415,7 +415,7 @@ func (sys *System) Close() {
 	}
 
 	for name, node := range sys.RollupNodes {
-		if err := node.Stop(postCtx); err != nil && !errors.Is(err, rollupNode.ErrAlreadyClosed) {
+		if err := node.Stop(postCtx); err != nil && !errors.Is(err, rollupNode.ErrAlreadyClosed) && !errors.Is(err, postCtx.Err()) {
 			combinedErr = errors.Join(combinedErr, fmt.Errorf("stop rollup node %v: %w", name, err))
 		}
 	}

op-node/node/config.go

@@ -172,3 +172,7 @@ func (cfg *Config) Check() error {
 	}
 	return nil
 }
+
+func (cfg *Config) P2PEnabled() bool {
+	return cfg.P2P != nil && !cfg.P2P.Disabled()
+}

op-node/node/node.go

@@ -8,6 +8,8 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/ethereum-optimism/optimism/op-node/rollup/sequencing"
+
 	"github.com/hashicorp/go-multierror"
 	"github.com/libp2p/go-libp2p/core/peer"
 
@@ -40,6 +42,8 @@ type closableSafeDB interface {
 }
 
 type OpNode struct {
+	// Retain the config to test for active features rather than test for runtime state.
+	cfg        *Config
 	log        log.Logger
 	appVersion string
 	metrics    *metrics.Metrics
@@ -93,6 +97,7 @@ func New(ctx context.Context, cfg *Config, log log.Logger, appVersion string, m
 	}
 
 	n := &OpNode{
+		cfg:        cfg,
 		log:        log,
 		appVersion: appVersion,
 		metrics:    m,
@@ -134,7 +139,7 @@ func (n *OpNode) init(ctx context.Context, cfg *Config) error {
 	if err := n.initP2PSigner(ctx, cfg); err != nil {
 		return fmt.Errorf("failed to init the P2P signer: %w", err)
 	}
-	if err := n.initP2P(ctx, cfg); err != nil {
+	if err := n.initP2P(cfg); err != nil {
 		return fmt.Errorf("failed to init the P2P stack: %w", err)
 	}
 	// Only expose the server at the end, ensuring all RPC backend components are initialized.
@@ -407,7 +412,7 @@ func (n *OpNode) initRPCServer(cfg *Config) error {
 	if err != nil {
 		return err
 	}
-	if n.p2pNode != nil {
+	if n.p2pEnabled() {
 		server.EnableP2P(p2p.NewP2PAPIBackend(n.p2pNode, n.log, n.metrics))
 	}
 	if cfg.RPC.EnableAdmin {
@@ -454,14 +459,20 @@ func (n *OpNode) initPProf(cfg *Config) error {
 	return nil
 }
 
-func (n *OpNode) initP2P(ctx context.Context, cfg *Config) error {
-	if cfg.P2P != nil {
+func (n *OpNode) p2pEnabled() bool {
+	return n.cfg.P2PEnabled()
+}
+
+func (n *OpNode) initP2P(cfg *Config) (err error) {
+	if n.p2pNode != nil {
+		panic("p2p node already initialized")
+	}
+	if n.p2pEnabled() {
 		// TODO(protocol-quest/97): Use EL Sync instead of CL Alt sync for fetching missing blocks in the payload queue.
-		p2pNode, err := p2p.NewNodeP2P(n.resourcesCtx, &cfg.Rollup, n.log, cfg.P2P, n, n.l2Source, n.runCfg, n.metrics, false)
-		if err != nil || p2pNode == nil {
-			return err
+		n.p2pNode, err = p2p.NewNodeP2P(n.resourcesCtx, &cfg.Rollup, n.log, cfg.P2P, n, n.l2Source, n.runCfg, n.metrics, false)
+		if err != nil {
+			return
 		}
-		n.p2pNode = p2pNode
 		if n.p2pNode.Dv5Udp() != nil {
 			go n.p2pNode.DiscoveryProcess(n.resourcesCtx, n.log, &cfg.Rollup, cfg.P2P.TargetPeers())
 		}
@@ -469,15 +480,14 @@ func (n *OpNode) initP2P(ctx context.Context, cfg *Config) error {
 	return nil
 }
 
-func (n *OpNode) initP2PSigner(ctx context.Context, cfg *Config) error {
+func (n *OpNode) initP2PSigner(ctx context.Context, cfg *Config) (err error) {
 	// the p2p signer setup is optional
 	if cfg.P2PSigner == nil {
-		return nil
+		return
 	}
 	// p2pSigner may still be nil, the signer setup may not create any signer, the signer is optional
-	var err error
 	n.p2pSigner, err = cfg.P2PSigner.SetupSigner(ctx)
-	return err
+	return
 }
 
 func (n *OpNode) Start(ctx context.Context) error {
@@ -533,7 +543,7 @@ func (n *OpNode) PublishL2Payload(ctx context.Context, envelope *eth.ExecutionPa
 	n.tracer.OnPublishL2Payload(ctx, envelope)
 
 	// publish to p2p, if we are running p2p at all
-	if n.p2pNode != nil {
+	if n.p2pEnabled() {
 		payload := envelope.ExecutionPayload
 		if n.p2pSigner == nil {
 			return fmt.Errorf("node has no p2p signer, payload %s cannot be published", payload.ID())
@@ -547,7 +557,7 @@ func (n *OpNode) PublishL2Payload(ctx context.Context, envelope *eth.ExecutionPa
 
 func (n *OpNode) OnUnsafeL2Payload(ctx context.Context, from peer.ID, envelope *eth.ExecutionPayloadEnvelope) error {
 	// ignore if it's from ourselves
-	if n.p2pNode != nil && from == n.p2pNode.Host().ID() {
+	if n.p2pEnabled() && from == n.p2pNode.Host().ID() {
 		return nil
 	}
 
@@ -568,9 +578,13 @@ func (n *OpNode) OnUnsafeL2Payload(ctx context.Context, from peer.ID, envelope *
 }
 
 func (n *OpNode) RequestL2Range(ctx context.Context, start, end eth.L2BlockRef) error {
-	if n.p2pNode != nil && n.p2pNode.AltSyncEnabled() {
+	if n.p2pEnabled() && n.p2pNode.AltSyncEnabled() {
 		if unixTimeStale(start.Time, 12*time.Hour) {
-			n.log.Debug("ignoring request to sync L2 range, timestamp is too old for p2p", "start", start, "end", end, "start_time", start.Time)
+			n.log.Debug(
+				"ignoring request to sync L2 range, timestamp is too old for p2p",
+				"start", start,
+				"end", end,
+				"start_time", start.Time)
 			return nil
 		}
 		return n.p2pNode.RequestL2Range(ctx, start, end)
@@ -606,10 +620,26 @@ func (n *OpNode) Stop(ctx context.Context) error {
 			result = multierror.Append(result, fmt.Errorf("failed to close RPC server: %w", err))
 		}
 	}
+
+	// Stop sequencer and report last hash. l2Driver can be nil if we're cleaning up a failed init.
+	if n.l2Driver != nil {
+		latestHead, err := n.l2Driver.StopSequencer(ctx)
+		switch {
+		case errors.Is(err, sequencing.ErrSequencerNotEnabled):
+		case errors.Is(err, driver.ErrSequencerAlreadyStopped):
+			n.log.Info("stopping node: sequencer already stopped", "latestHead", latestHead)
+		case err == nil:
+			n.log.Info("stopped sequencer", "latestHead", latestHead)
+		default:
+			result = multierror.Append(result, fmt.Errorf("error stopping sequencer: %w", err))
+		}
+	}
 	if n.p2pNode != nil {
 		if err := n.p2pNode.Close(); err != nil {
 			result = multierror.Append(result, fmt.Errorf("failed to close p2p node: %w", err))
 		}
+		// Prevent further use of p2p.
+		n.p2pNode = nil
 	}
 	if n.p2pSigner != nil {
 		if err := n.p2pSigner.Close(); err != nil {

op-node/p2p/config.go

@@ -48,6 +48,7 @@ type HostMetrics interface {
 // SetupP2P provides a host and discovery service for usage in the rollup node.
 type SetupP2P interface {
 	Check() error
+	// Looks like this was started to prevent partially inited p2p.
 	Disabled() bool
 	// Host creates a libp2p host service. Returns nil, nil if p2p is disabled.
 	Host(log log.Logger, reporter metrics.Reporter, metrics HostMetrics) (host.Host, error)

op-node/p2p/node.go

@@ -52,10 +52,23 @@ type NodeP2P struct {
 
 // NewNodeP2P creates a new p2p node, and returns a reference to it. If the p2p is disabled, it returns nil.
 // If metrics are configured, a bandwidth monitor will be spawned in a goroutine.
-func NewNodeP2P(resourcesCtx context.Context, rollupCfg *rollup.Config, log log.Logger, setup SetupP2P, gossipIn GossipIn, l2Chain L2Chain, runCfg GossipRuntimeConfig, metrics metrics.Metricer, elSyncEnabled bool) (*NodeP2P, error) {
+func NewNodeP2P(
+	resourcesCtx context.Context,
+	rollupCfg *rollup.Config,
+	log log.Logger,
+	setup SetupP2P,
+	gossipIn GossipIn,
+	l2Chain L2Chain,
+	runCfg GossipRuntimeConfig,
+	metrics metrics.Metricer,
+	elSyncEnabled bool,
+) (*NodeP2P, error) {
 	if setup == nil {
 		return nil, errors.New("p2p node cannot be created without setup")
 	}
+	if setup.Disabled() {
+		return nil, errors.New("SetupP2P.Disabled is true")
+	}
 	var n NodeP2P
 	if err := n.init(resourcesCtx, rollupCfg, log, setup, gossipIn, l2Chain, runCfg, metrics, elSyncEnabled); err != nil {
 		closeErr := n.Close()
@@ -65,12 +78,24 @@ func NewNodeP2P(resourcesCtx context.Context, rollupCfg *rollup.Config, log log.
 		return nil, err
 	}
 	if n.host == nil {
-		return nil, nil
+		// See prior comment about n.host optionality:
+		// TODO(CLI-4016): host is not optional, NodeP2P as a whole is.
+		panic("host is not optional if p2p is enabled")
 	}
 	return &n, nil
 }
 
-func (n *NodeP2P) init(resourcesCtx context.Context, rollupCfg *rollup.Config, log log.Logger, setup SetupP2P, gossipIn GossipIn, l2Chain L2Chain, runCfg GossipRuntimeConfig, metrics metrics.Metricer, elSyncEnabled bool) error {
+func (n *NodeP2P) init(
+	resourcesCtx context.Context,
+	rollupCfg *rollup.Config,
+	log log.Logger,
+	setup SetupP2P,
+	gossipIn GossipIn,
+	l2Chain L2Chain,
+	runCfg GossipRuntimeConfig,
+	metrics metrics.Metricer,
+	elSyncEnabled bool,
+) error {
 	bwc := p2pmetrics.NewBandwidthCounter()
 
 	n.log = log
@@ -85,8 +110,6 @@ func (n *NodeP2P) init(resourcesCtx context.Context, rollupCfg *rollup.Config, l
 		return fmt.Errorf("failed to start p2p host: %w", err)
 	}
 
-	// TODO(CLI-4016): host is not optional, NodeP2P as a whole is. This if statement is wrong
-	if n.host != nil {
 	// Enable extra features, if any. During testing we don't setup the most advanced host all the time.
 	if extra, ok := n.host.(ExtraHostFeatures); ok {
 		n.gater = extra.ConnectionGater()
@@ -164,7 +187,6 @@ func (n *NodeP2P) init(resourcesCtx context.Context, rollupCfg *rollup.Config, l
 		n.peerMonitor.Start()
 	}
 	n.appScorer.start()
-	}
 	return nil
 }