feat: add dns-discovery flags to wakunode and chat2 example (#52)

examples/chat2/go.mod

@@ -5,13 +5,13 @@ go 1.15
 replace github.com/status-im/go-waku => ../..
 
 require (
-	github.com/ethereum/go-ethereum v1.10.1
+	github.com/ethereum/go-ethereum v1.10.4
 	github.com/gdamore/tcell/v2 v2.2.0
 	github.com/golang/protobuf v1.5.2
 	github.com/ipfs/go-log v1.0.5
 	github.com/libp2p/go-libp2p-core v0.8.6
 	github.com/rivo/tview v0.0.0-20210312174852-ae9464cc3598
 	github.com/status-im/go-waku v0.0.0-20210428201044-3d8aae5b81b9
-	golang.org/x/crypto v0.0.0-20210506145944-38f3c27a63bf
+	golang.org/x/crypto v0.0.0-20210616213533-5ff15b29337e
 	google.golang.org/protobuf v1.26.0
 )

examples/chat2/main.go

@@ -18,6 +18,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	logging "github.com/ipfs/go-log"
 	"github.com/libp2p/go-libp2p-core/peer"
+	"github.com/status-im/go-waku/waku/v2/discovery"
 	"github.com/status-im/go-waku/waku/v2/node"
 	"github.com/status-im/go-waku/waku/v2/protocol/store"
 )
@@ -42,6 +43,10 @@ func main() {
 	lightPushNodeFlag := flag.String("lightpushnode", "", "Multiaddr of peer to to request lightpush of published messages")
 	keepAliveFlag := flag.Int64("keep-alive", 300, "interval in seconds for pinging peers to keep the connection alive.")
 
+	dnsDiscoveryFlag := flag.Bool("dns-discovery", false, "enable dns discovery")
+	dnsDiscoveryUrlFlag := flag.String("dns-discovery-url", "", "URL for DNS node list in format 'enrtree://<key>@<fqdn>'")
+	dnsDiscoveryNameServerFlag := flag.String("dns-discovery-nameserver", "", "DNS name server IP to query (empty to use system default)")
+
 	flag.Parse()
 
 	hostAddr, _ := net.ResolveTCPAddr("tcp", fmt.Sprintf("0.0.0.0:%d", *port))
@@ -146,6 +151,25 @@ func main() {
 
 		}
 
+		enableDiscovery := *dnsDiscoveryFlag
+		dnsDiscoveryUrl := *dnsDiscoveryUrlFlag
+		dnsDiscoveryNameServer := *dnsDiscoveryNameServerFlag
+
+		if enableDiscovery && dnsDiscoveryUrl != "" {
+			ui.displayMessage(fmt.Sprintf("attempting DNS discovery with %s", dnsDiscoveryUrl))
+			multiaddresses, err := discovery.RetrieveNodes(ctx, dnsDiscoveryUrl, discovery.WithNameserver(dnsDiscoveryNameServer))
+			if err != nil {
+				ui.displayMessage("DNS discovery error: " + err.Error())
+			} else {
+				for _, m := range multiaddresses {
+					err = wakuNode.DialPeerWithMultiAddress(m)
+					if err != nil {
+						ui.displayMessage("error dialing peer: " + err.Error())
+					}
+				}
+			}
+		}
+
 		if len(storenode) == 0 {
 			ui.displayMessage(fmt.Sprintf("No store node configured. Choosing one at random from %s fleet...", *fleetFlag))
 			storenode = getRandomFleetNode(fleetData, *fleetFlag)

waku/node.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	dssql "github.com/ipfs/go-ds-sql"
 	logging "github.com/ipfs/go-log"
 	"github.com/libp2p/go-libp2p"
@@ -25,6 +26,7 @@ import (
 	"github.com/status-im/go-waku/waku/persistence"
 	"github.com/status-im/go-waku/waku/persistence/sqlite"
 
+	"github.com/status-im/go-waku/waku/v2/discovery"
 	"github.com/status-im/go-waku/waku/v2/node"
 	"github.com/status-im/go-waku/waku/v2/protocol/relay"
 )
@@ -74,6 +76,9 @@ var rootCmd = &cobra.Command{
 		enableMetrics, _ := cmd.Flags().GetBool("metrics")
 		metricsAddress, _ := cmd.Flags().GetString("metrics-address")
 		metricsPort, _ := cmd.Flags().GetInt("metrics-port")
+		enableDnsDiscovery, _ := cmd.Flags().GetBool("dns-discovery")
+		dnsDiscoveryUrl, _ := cmd.Flags().GetString("dns-discovery-url")
+		dnsDiscoveryNameServer, _ := cmd.Flags().GetString("dns-discovery-nameserver")
 
 		hostAddr, _ := net.ResolveTCPAddr("tcp", fmt.Sprint("0.0.0.0:", port))
 
@@ -172,8 +177,9 @@ var rootCmd = &cobra.Command{
 		} else {
 			if storenode != "" {
 				_, err = wakuNode.AddStorePeer(storenode)
-				checkError(err, "Error adding store peer")
+				if err != nil {
-
+					log.Error("error adding store peer ", err)
+				}
 			}
 		}
 
@@ -181,11 +187,40 @@ var rootCmd = &cobra.Command{
 			for _, n := range staticnodes {
 				go func(node string) {
 					err = wakuNode.DialPeer(node)
-					checkError(err, "Error dialing peer")
+					if err != nil {
+						log.Error("error dialing peer ", err)
+					}
 				}(n)
 			}
 		}
 
+		if enableDnsDiscovery {
+
+			for _, addr := range wakuNode.ListenAddresses() {
+				ip, _ := addr.ValueForProtocol(multiaddr.P_IP4)
+				enr := enode.NewV4(&prvKey.PublicKey, net.ParseIP(ip), hostAddr.Port, 0)
+				log.Info("ENR: ", enr)
+			}
+
+			if dnsDiscoveryUrl != "" {
+				log.Info("attempting DNS discovery with ", dnsDiscoveryUrl)
+				multiaddresses, err := discovery.RetrieveNodes(ctx, dnsDiscoveryUrl, discovery.WithNameserver(dnsDiscoveryNameServer))
+				if err != nil {
+					log.Warn("dns discovery error ", err)
+				} else {
+					log.Info("found dns entries ", multiaddresses)
+					for _, m := range multiaddresses {
+						err = wakuNode.DialPeerWithMultiAddress(m)
+						if err != nil {
+							log.Error("error dialing peer ", err)
+						}
+					}
+				}
+			} else {
+				log.Fatal("DNS discovery URL is required")
+			}
+		}
+
 		if len(lightpushnodes) > 0 && !lightpush {
 			checkError(errors.New("LightPush protocol was not started"), "")
 		} else {
@@ -260,6 +295,9 @@ func init() {
 	rootCmd.Flags().Bool("metrics", false, "Enable the metrics server")
 	rootCmd.Flags().String("metrics-address", "127.0.0.1", "Listening address of the metrics server")
 	rootCmd.Flags().Int("metrics-port", 8008, "Listening HTTP port of the metrics server")
+	rootCmd.Flags().Bool("dns-discovery", false, "enable dns discovery")
+	rootCmd.Flags().String("dns-discovery-url", "", "URL for DNS node list in format 'enrtree://<key>@<fqdn>'")
+	rootCmd.Flags().String("dns-discovery-nameserver", "", "DNS nameserver IP to query (empty to use system's default)")
 }
 
 func initConfig() {

waku/v2/discovery/enr.go

@@ -1,6 +1,7 @@
 package discovery
 
 import (
+	"context"
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/p2p/dnsdisc"
@@ -10,12 +11,32 @@ import (
 	ma "github.com/multiformats/go-multiaddr"
 )
 
+type DnsDiscoveryParameters struct {
+	nameserver string
+}
+
+type DnsDiscoveryOption func(*DnsDiscoveryParameters)
+
+// WithMultiaddress is a WakuNodeOption that configures libp2p to listen on a list of multiaddresses
+func WithNameserver(nameserver string) DnsDiscoveryOption {
+	return func(params *DnsDiscoveryParameters) {
+		params.nameserver = nameserver
+	}
+}
+
 // RetrieveNodes returns a list of multiaddress given a url to a DNS discoverable
 // ENR tree
-func RetrieveNodes(url string) ([]ma.Multiaddr, error) {
+func RetrieveNodes(ctx context.Context, url string, opts ...DnsDiscoveryOption) ([]ma.Multiaddr, error) {
 	var multiAddrs []ma.Multiaddr
 
-	client := dnsdisc.NewClient(dnsdisc.Config{})
+	params := new(DnsDiscoveryParameters)
+	for _, opt := range opts {
+		opt(params)
+	}
+
+	client := dnsdisc.NewClient(dnsdisc.Config{
+		Resolver: GetResolver(ctx, params.nameserver),
+	})
 
 	tree, err := client.SyncTree(url)
 	if err != nil {
@@ -23,19 +44,18 @@ func RetrieveNodes(url string) ([]ma.Multiaddr, error) {
 	}
 
 	for _, node := range tree.Nodes() {
-		m, err := enodeToMultiAddr(node)
+		m, err := EnodeToMultiAddr(node)
 		if err != nil {
 			return nil, err
 		}
 
 		multiAddrs = append(multiAddrs, m)
-
 	}
 
 	return multiAddrs, nil
 }
 
-func enodeToMultiAddr(node *enode.Node) (ma.Multiaddr, error) {
+func EnodeToMultiAddr(node *enode.Node) (ma.Multiaddr, error) {
 	peerID, err := peer.IDFromPublicKey(&ECDSAPublicKey{node.Pubkey()})
 	if err != nil {
 		return nil, err

waku/v2/discovery/resolver.go

@@ -0,0 +1,20 @@
+package discovery
+
+import (
+	"context"
+	"net"
+)
+
+func GetResolver(ctx context.Context, nameserver string) *net.Resolver {
+	if nameserver == "" {
+		return net.DefaultResolver
+	}
+
+	return &net.Resolver{
+		PreferGo: true,
+		Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+			d := net.Dialer{}
+			return d.DialContext(ctx, network, net.JoinHostPort(nameserver, "53"))
+		},
+	}
+}

waku/v2/node/wakunode2.go

@@ -352,11 +352,11 @@ func (w *WakuNode) HasHistory() bool {
 	return false
 }
 
-func (w *WakuNode) ListenAddresses() []string {
+func (w *WakuNode) ListenAddresses() []ma.Multiaddr {
 	hostInfo, _ := ma.NewMultiaddr(fmt.Sprintf("/p2p/%s", w.host.ID().Pretty()))
-	var result []string
+	var result []ma.Multiaddr
 	for _, addr := range w.host.Addrs() {
-		result = append(result, addr.Encapsulate(hostInfo).String())
+		result = append(result, addr.Encapsulate(hostInfo))
 	}
 	return result
 }
@@ -690,6 +690,15 @@ func (node *WakuNode) LightPush(ctx context.Context, message *pb.WakuMessage, to
 	}
 }
 
+func (w *WakuNode) DialPeerWithMultiAddress(address ma.Multiaddr) error {
+	info, err := peer.AddrInfoFromP2pAddr(address)
+	if err != nil {
+		return err
+	}
+
+	return w.connect(*info)
+}
+
 func (w *WakuNode) DialPeer(address string) error {
 	p, err := ma.NewMultiaddr(address)
 	if err != nil {