chore: change peers caps to []string and change DNS discovery logic (#…

…411)

* chore: cleanup

* fix import

* fix logic

* fix: simplify logic

cmd/p2p/sensor/sensor.go

@@ -251,26 +251,30 @@ var SensorCmd = &cobra.Command{
 		sub := server.SubscribeEvents(events)
 		defer sub.Unsubscribe()
 
-		ticker := time.NewTicker(2 * time.Second) // Ticker for recurring tasks every 2 seconds
-		hourlyTicker := time.NewTicker(time.Hour) // Ticker for running DNS discovery every hour
+		ticker := time.NewTicker(2 * time.Second) // Ticker for recurring tasks every 2 seconds.
+		hourlyTicker := time.NewTicker(time.Hour) // Ticker for running DNS discovery every hour.
 		defer ticker.Stop()
 		defer hourlyTicker.Stop()
 
 		signals := make(chan os.Signal, 1)
 		signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
 
+		// peers represents the peer map that is used to write to the nodes.json
+		// file. This is helpful when restarting the node with the --quickstart flag
+		// enabled. This map does not represent the peers that are currently
+		// connected to the sensor. To do that use `server.Peers()` instead.
 		peers := make(map[enode.ID]string)
 		var peersMutex sync.Mutex
 
 		for _, node := range inputSensorParams.nodes {
-			// Map node URLs to node IDs to avoid duplicates
+			// Map node URLs to node IDs to avoid duplicates.
 			peers[node.ID()] = node.URLv4()
 		}
 
 		go handleAPI(&server, msgCounter)
 
-		// Run DNS discovery immediately at startup
-		go handleDNSDiscovery(&server, peers, &peersMutex)
+		// Run DNS discovery immediately at startup.
+		go handleDNSDiscovery(&server)
 
 		for {
 			select {
@@ -282,9 +286,9 @@ var SensorCmd = &cobra.Command{
 
 				db.WritePeers(context.Background(), server.Peers())
 			case peer := <-opts.Peers:
-				// Lock the peers map before modifying it
+				// Lock the peers map before modifying it.
 				peersMutex.Lock()
-				// Update the peer list and the nodes file
+				// Update the peer list and the nodes file.
 				if _, ok := peers[peer.ID()]; !ok {
 					peers[peer.ID()] = peer.URLv4()
 
@@ -294,7 +298,7 @@ var SensorCmd = &cobra.Command{
 				}
 				peersMutex.Unlock()
 			case <-hourlyTicker.C:
-				go handleDNSDiscovery(&server, peers, &peersMutex)
+				go handleDNSDiscovery(&server)
 			case <-signals:
 				// This gracefully stops the sensor so that the peers can be written to
 				// the nodes file.
@@ -389,7 +393,7 @@ func handleAPI(server *ethp2p.Server, counter *prometheus.CounterVec) {
 // handleDNSDiscovery performs DNS-based peer discovery and adds new peers to
 // the p2p server. It syncs the DNS discovery tree and adds any newly discovered
 // peers not already in the peers map.
-func handleDNSDiscovery(server *ethp2p.Server, peers map[enode.ID]string, peersMutex *sync.Mutex) {
+func handleDNSDiscovery(server *ethp2p.Server) {
 	if len(inputSensorParams.DiscoveryDNS) == 0 {
 		return
 	}
@@ -405,26 +409,20 @@ func handleDNSDiscovery(server *ethp2p.Server, peers map[enode.ID]string, peersM
 		return
 	}
 
-	// Log the number of nodes in the tree
+	// Log the number of nodes in the tree.
 	log.Info().
 		Int("unique_nodes", len(tree.Nodes())).
 		Msg("Successfully synced DNS discovery tree")
 
-	// Lock the peers map and server operations
-	peersMutex.Lock()
-	defer peersMutex.Unlock()
-
-	// Add DNS-discovered peers
+	// Add DNS-discovered peers.
 	for _, node := range tree.Nodes() {
-		if _, ok := peers[node.ID()]; ok {
-			continue
-		}
-
 		log.Debug().
 			Str("enode", node.URLv4()).
-			Msg("Discovered new peer through DNS")
+			Msg("Discovered peer through DNS")
 
-		// Instruct server to connect to the new peer
+		// Add the peer to the static node set. The server itself handles whether to
+		// connect to the peer if it's already connected. If a node is part of the
+		// static peer set, the server will handle reconnecting after disconnects.
 		server.AddPeer(node)
 	}
 

p2p/database/datastore.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"math/big"
-	"strings"
 	"time"
 
 	"cloud.google.com/go/datastore"
@@ -107,7 +106,7 @@ type DatastoreTransaction struct {
 
 type DatastorePeer struct {
 	Name         string
-	Caps         string
+	Caps         []string
 	URL          string
 	LastSeenBy   string
 	TimeLastSeen time.Time
@@ -266,7 +265,7 @@ func (d *Datastore) WritePeers(ctx context.Context, peers []*p2p.Peer) {
 			keys = append(keys, datastore.NameKey(PeersKind, peer.ID().String(), nil))
 			dsPeers = append(dsPeers, &DatastorePeer{
 				Name:         peer.Fullname(),
-				Caps:         strings.Join(peer.Info().Caps, ","),
+				Caps:         peer.Info().Caps,
 				URL:          peer.Node().URLv4(),
 				LastSeenBy:   d.sensorID,
 				TimeLastSeen: now,