feat(manager): allow starting node when sequencer is sentinel

block/manager.go

@@ -232,7 +232,9 @@ func (m *Manager) Start(ctx context.Context) error {
 	if m.State.GetProposer() == nil {
 		m.logger.Info("No proposer on the rollapp, fallback to the hub proposer, if available")
 		err := m.UpdateProposerFromSL()
-		if err != nil {
+		if errors.Is(err, settlement.ErrProposerIsSentinel) {
+			m.freezeNode(fmt.Errorf("unable to start without new proposer at height %d", m.State.NextHeight()))
+		} else if err != nil {
 			return err
 		}
 		_, err = m.Store.SaveState(m.State, nil)
@@ -246,7 +248,9 @@ func (m *Manager) Start(ctx context.Context) error {
 	// for this case, 2 nodes will get `true` for `AmIProposer` so the l2 proposer can produce blocks and the hub proposer can submit his last batch.
 	// The hub proposer, after sending the last state update, will panic and restart as full node.
 	amIProposerOnSL, err := m.AmIProposerOnSL()
-	if err != nil {
+	if errors.Is(err, settlement.ErrProposerIsSentinel) {
+		amIProposerOnSL = false
+	} else if err != nil {
 		return fmt.Errorf("am i proposer on SL: %w", err)
 	}
 

block/modes.go

@@ -58,7 +58,9 @@ func (m *Manager) runAsProposer(ctx context.Context, eg *errgroup.Group) error {
 
 	// it is checked again whether the node is the active proposer, since this could have changed after syncing.
 	amIProposerOnSL, err := m.AmIProposerOnSL()
-	if err != nil {
+	if errors.Is(err, settlement.ErrProposerIsSentinel) {
+		amIProposerOnSL = false
+	} else if err != nil {
 		return fmt.Errorf("am i proposer on SL: %w", err)
 	}
 	if !amIProposerOnSL {

block/sequencers.go

@@ -3,8 +3,11 @@ package block
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"time"
+
+	"github.com/dymensionxyz/dymint/settlement"
 )
 
 const (
@@ -94,7 +97,11 @@ func (m *Manager) ShouldRotate() (bool, error) {
 	// At this point we know that there is a next proposer,
 	// so we should rotate only if we are the current proposer on the hub
 	amIProposerOnSL, err := m.AmIProposerOnSL()
-	if err != nil {
+
+	// if no proposer assigned, return false without error
+	if errors.Is(err, settlement.ErrProposerIsSentinel) {
+		return false, nil
+	} else if err != nil {
 		return false, fmt.Errorf("am i proposer on SL: %w", err)
 	}
 	return amIProposerOnSL, nil

p2p/block.go

@@ -55,6 +55,7 @@ func (b *BlockData) FromProto(other *pb.BlockData) error {
 
 // Validate run basic validation on the p2p block received
 func (b *BlockData) Validate(proposerPubKey tmcrypto.PubKey) error {
+
 	if err := b.Block.ValidateBasic(); err != nil {
 		return err
 	}

settlement/dymension/dymension.go

@@ -346,8 +346,8 @@ func (c *Client) GetProposerAtHeight(height int64) (*types.Sequencer, error) {
 		}
 	}
 
-	if proposerAddr == SENTINEL_PROPOSER {
-		return nil, fmt.Errorf("proposer is sentinel")
+	if proposerAddr == "" || proposerAddr == SENTINEL_PROPOSER {
+		return nil, settlement.ErrProposerIsSentinel
 	}
 
 	// Find and return the matching sequencer
@@ -538,7 +538,7 @@ func (c *Client) GetNextProposer() (*types.Sequencer, error) {
 	if !found {
 		return nil, nil
 	}
-	if nextAddr == SENTINEL_PROPOSER {
+	if nextAddr == "" || nextAddr == SENTINEL_PROPOSER {
 		return &types.Sequencer{}, nil
 	}
 

settlement/errors.go

@@ -9,6 +9,9 @@ import (
 // ErrBatchNotAccepted is returned when a batch is not accepted by the settlement layer.
 var ErrBatchNotAccepted = fmt.Errorf("batch not accepted: %w", gerrc.ErrUnknown)
 
+// ErrProposerIsSentinel is returned when a rollapp has no sequencer assigned.
+var ErrProposerIsSentinel = fmt.Errorf("proposer is sentinel")
+
 type ErrNextSequencerAddressFraud struct {
 	Expected string
 	Actual   string