feat: peer exchange filter by shard

waku/v2/protocol/peer_exchange/client.go

@@ -12,6 +12,7 @@ import (
 	"github.com/libp2p/go-msgio/pbio"
 	"github.com/waku-org/go-waku/waku/v2/peermanager"
 	"github.com/waku-org/go-waku/waku/v2/peerstore"
+	"github.com/waku-org/go-waku/waku/v2/protocol"
 	wenr "github.com/waku-org/go-waku/waku/v2/protocol/enr"
 	"github.com/waku-org/go-waku/waku/v2/protocol/peer_exchange/pb"
 	"github.com/waku-org/go-waku/waku/v2/service"
@@ -43,10 +44,16 @@ func (wakuPX *WakuPeerExchange) Request(ctx context.Context, numPeers int, opts
 	}
 
 	if params.pm != nil && params.selectedPeer == "" {
+		pubsubTopics := []string{}
+		if params.clusterID != 0 {
+			pubsubTopics = append(pubsubTopics,
+				protocol.NewStaticShardingPubsubTopic(uint16(params.clusterID), uint16(params.shard)).String())
+		}
 		selectedPeers, err := wakuPX.pm.SelectPeers(
 			peermanager.PeerSelectionCriteria{
 				SelectionType: params.peerSelectionType,
 				Proto:         PeerExchangeID_v20alpha1,
+				PubsubTopics:  pubsubTopics,
 				SpecificPeers: params.preferredPeers,
 				Ctx:           ctx,
 			},
@@ -93,10 +100,10 @@ func (wakuPX *WakuPeerExchange) Request(ctx context.Context, numPeers int, opts
 
 	stream.Close()
 
-	return wakuPX.handleResponse(ctx, responseRPC.Response)
+	return wakuPX.handleResponse(ctx, responseRPC.Response, params)
 }
 
-func (wakuPX *WakuPeerExchange) handleResponse(ctx context.Context, response *pb.PeerExchangeResponse) error {
+func (wakuPX *WakuPeerExchange) handleResponse(ctx context.Context, response *pb.PeerExchangeResponse, params *PeerExchangeParameters) error {
 	var discoveredPeers []struct {
 		addrInfo peer.AddrInfo
 		enr      *enode.Node
@@ -112,6 +119,16 @@ func (wakuPX *WakuPeerExchange) handleResponse(ctx context.Context, response *pb
 			return err
 		}
 
+		if params.clusterID != 0 {
+			wakuPX.log.Debug("clusterID is non zero, filtering by shard")
+			rs, err := wenr.RelaySharding(enrRecord)
+			if err != nil || rs == nil || !rs.Contains(uint16(params.clusterID), uint16(params.shard)) {
+				wakuPX.log.Debug("peer doesn't matches filter", zap.Int("shard", params.shard))
+				continue
+			}
+			wakuPX.log.Debug("peer matches filter", zap.Int("shard", params.shard))
+		}
+
 		enodeRecord, err := enode.New(enode.ValidSchemes, enrRecord)
 		if err != nil {
 			wakuPX.log.Error("creating enode record", zap.Error(err))

waku/v2/protocol/peer_exchange/waku_peer_exchange_option.go

@@ -18,6 +18,8 @@ type PeerExchangeParameters struct {
 	preferredPeers    peer.IDSlice
 	pm                *peermanager.PeerManager
 	log               *zap.Logger
+	shard             int
+	clusterID         int
 }
 
 type PeerExchangeOption func(*PeerExchangeParameters) error
@@ -77,3 +79,12 @@ func DefaultOptions(host host.Host) []PeerExchangeOption {
 		WithAutomaticPeerSelection(),
 	}
 }
+
+// Use this if you want to filter peers by specific shards
+func FilterByShard(clusterID int, shard int) PeerExchangeOption {
+	return func(params *PeerExchangeParameters) error {
+		params.shard = shard
+		params.clusterID = clusterID
+		return nil
+	}
+}

waku/v2/protocol/peer_exchange/waku_peer_exchange_test.go

@@ -6,11 +6,13 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/libp2p/go-libp2p/core/peerstore"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/stretchr/testify/require"
 	"github.com/waku-org/go-waku/tests"
 	"github.com/waku-org/go-waku/waku/v2/discv5"
+	"github.com/waku-org/go-waku/waku/v2/protocol"
 	wenr "github.com/waku-org/go-waku/waku/v2/protocol/enr"
 	"github.com/waku-org/go-waku/waku/v2/utils"
 )
@@ -88,3 +90,98 @@ func TestRetrieveProvidePeerExchangePeers(t *testing.T) {
 	px1.Stop()
 	px3.Stop()
 }
+
+func TestRetrieveFilteredPeerExchangePeers(t *testing.T) {
+	// H1
+	host1, _, prvKey1 := tests.CreateHost(t)
+	udpPort1, err := tests.FindFreePort(t, "127.0.0.1", 3)
+	require.NoError(t, err)
+	ip1, _ := tests.ExtractIP(host1.Addrs()[0])
+	l1, err := tests.NewLocalnode(prvKey1, ip1, udpPort1, wenr.NewWakuEnrBitfield(false, false, false, true), nil, utils.Logger())
+	require.NoError(t, err)
+
+	discv5PeerConn1 := discv5.NewTestPeerDiscoverer()
+	d1, err := discv5.NewDiscoveryV5(prvKey1, l1, discv5PeerConn1, prometheus.DefaultRegisterer, utils.Logger(), discv5.WithUDPPort(uint(udpPort1)))
+	require.NoError(t, err)
+	d1.SetHost(host1)
+
+	// H2
+	host2, _, prvKey2 := tests.CreateHost(t)
+	ip2, _ := tests.ExtractIP(host2.Addrs()[0])
+	udpPort2, err := tests.FindFreePort(t, "127.0.0.1", 3)
+	require.NoError(t, err)
+	l2, err := tests.NewLocalnode(prvKey2, ip2, udpPort2, wenr.NewWakuEnrBitfield(false, false, false, true), nil, utils.Logger())
+	require.NoError(t, err)
+	rs, err := protocol.NewRelayShards(1, 2)
+	require.NoError(t, err)
+	l2.Set(enr.WithEntry(wenr.ShardingBitVectorEnrField, rs.BitVector()))
+	discv5PeerConn2 := discv5.NewTestPeerDiscoverer()
+	d2, err := discv5.NewDiscoveryV5(prvKey2, l2, discv5PeerConn2, prometheus.DefaultRegisterer, utils.Logger(), discv5.WithUDPPort(uint(udpPort2)), discv5.WithBootnodes([]*enode.Node{d1.Node()}))
+	require.NoError(t, err)
+	d2.SetHost(host2)
+
+	// H3
+	host3, _, _ := tests.CreateHost(t)
+
+	defer d1.Stop()
+	defer d2.Stop()
+	defer host1.Close()
+	defer host2.Close()
+	defer host3.Close()
+
+	err = d1.Start(context.Background())
+	require.NoError(t, err)
+
+	err = d2.Start(context.Background())
+	require.NoError(t, err)
+
+	time.Sleep(3 * time.Second) // Wait some time for peers to be discovered
+
+	// mount peer exchange
+	pxPeerConn1 := discv5.NewTestPeerDiscoverer()
+	px1, err := NewWakuPeerExchange(d1, pxPeerConn1, nil, prometheus.DefaultRegisterer, utils.Logger())
+	require.NoError(t, err)
+	px1.SetHost(host1)
+
+	pxPeerConn3 := discv5.NewTestPeerDiscoverer()
+	px3, err := NewWakuPeerExchange(nil, pxPeerConn3, nil, prometheus.DefaultRegisterer, utils.Logger())
+	require.NoError(t, err)
+	px3.SetHost(host3)
+
+	err = px1.Start(context.Background())
+	require.NoError(t, err)
+
+	err = px3.Start(context.Background())
+	require.NoError(t, err)
+
+	host3.Peerstore().AddAddrs(host1.ID(), host1.Addrs(), peerstore.PermanentAddrTTL)
+	err = host3.Peerstore().AddProtocols(host1.ID(), PeerExchangeID_v20alpha1)
+	require.NoError(t, err)
+
+	//Try with shard that is not registered.
+	err = px3.Request(context.Background(), 1, WithPeer(host1.ID()), FilterByShard(1, 3))
+	require.NoError(t, err)
+
+	time.Sleep(3 * time.Second) //  Give the algorithm some time to work its magic
+
+	require.False(t, pxPeerConn3.HasPeer(host2.ID()))
+
+	//Try without shard filtering
+
+	err = px3.Request(context.Background(), 1, WithPeer(host1.ID()))
+	require.NoError(t, err)
+
+	time.Sleep(3 * time.Second) //  Give the algorithm some time to work its magic
+
+	require.True(t, pxPeerConn3.HasPeer(host2.ID()))
+
+	err = px3.Request(context.Background(), 1, WithPeer(host1.ID()), FilterByShard(1, 2))
+	require.NoError(t, err)
+
+	time.Sleep(3 * time.Second) //  Give the algorithm some time to work its magic
+
+	require.True(t, pxPeerConn3.HasPeer(host2.ID()))
+
+	px1.Stop()
+	px3.Stop()
+}

waku/v2/protocol/shard.go

@@ -268,3 +268,11 @@ func GeneratePubsubToContentTopicMap(pubsubTopic string, contentTopics []string)
 	}
 	return pubSubTopicMap, nil
 }
+
+func ShardsToTopics(clusterId int, shards []int) []string {
+	pubsubTopics := make([]string, len(shards))
+	for i, shard := range shards {
+		pubsubTopics[i] = NewStaticShardingPubsubTopic(uint16(clusterId), uint16(shard)).String()
+	}
+	return pubsubTopics
+}