Do not engage in PubSub with the bootstrappers (#355)

node/p2p/blossomsub.go

@@ -416,7 +416,18 @@ func NewBlossomSub(
 			GraylistThreshold:           -10000,
 			AcceptPXThreshold:           1,
 			OpportunisticGraftThreshold: 2,
-		}))
+		},
+	))
+	blossomOpts = append(blossomOpts, blossomsub.WithPeerFilter(internal.NewStaticPeerFilter(
+		// We filter out the bootstrap peers explicitly from BlossomSub
+		// as they do not subscribe to relevant topics anymore.
+		// However, the beacon is one of the bootstrap peers usually
+		// and as such it gets special treatment - it is the only bootstrap
+		// peer which is engaged in the network.
+		[]peer.ID{internal.BeaconPeerID(uint(p2pConfig.Network))},
+		internal.PeerAddrInfosToPeerIDSlice(bootstrappers),
+		true,
+	)))
 
 	params := mergeDefaults(p2pConfig)
 	rt := blossomsub.NewBlossomSubRouter(h, params, bs.network)

node/p2p/internal/beacon.go

@@ -0,0 +1,24 @@
+package internal
+
+import (
+	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"source.quilibrium.com/quilibrium/monorepo/node/config"
+)
+
+// BeaconPeerID returns the peer ID of the beacon node.
+func BeaconPeerID(network uint) peer.ID {
+	genesis, err := config.DownloadAndVerifyGenesis(network)
+	if err != nil {
+		panic(err)
+	}
+	pub, err := crypto.UnmarshalEd448PublicKey(genesis.Beacon)
+	if err != nil {
+		panic(err)
+	}
+	peerID, err := peer.IDFromPublicKey(pub)
+	if err != nil {
+		panic(err)
+	}
+	return peerID
+}

node/p2p/internal/peer_filter.go

@@ -0,0 +1,31 @@
+package internal
+
+import (
+	"github.com/libp2p/go-libp2p/core/peer"
+	blossomsub "source.quilibrium.com/quilibrium/monorepo/go-libp2p-blossomsub"
+)
+
+// NewStaticPeerFilter creates a new static peer filter.
+// The allowList is a list of peers that are allowed to mesh.
+// The blockList is a list of peers that are blocked from meshing.
+// The def is the default value for peers that are not in the allowList or blockList.
+// The allowList has priority over the blockList.
+func NewStaticPeerFilter(allowList, blockList []peer.ID, def bool) blossomsub.PeerFilter {
+	allowed := make(map[peer.ID]struct{})
+	for _, p := range allowList {
+		allowed[p] = struct{}{}
+	}
+	blocked := make(map[peer.ID]struct{})
+	for _, p := range blockList {
+		blocked[p] = struct{}{}
+	}
+	return func(peerID peer.ID, _ []byte) bool {
+		if _, ok := allowed[peerID]; ok {
+			return true
+		}
+		if _, ok := blocked[peerID]; ok {
+			return false
+		}
+		return def
+	}
+}