Merge pull request #378 from upperwal/default_listener

Added a Default listener

defaults.go

@@ -10,6 +10,7 @@ import (
 	secio "github.com/libp2p/go-libp2p-secio"
 	tcp "github.com/libp2p/go-tcp-transport"
 	ws "github.com/libp2p/go-ws-transport"
+	multiaddr "github.com/multiformats/go-multiaddr"
 	mplex "github.com/whyrusleeping/go-smux-multiplex"
 	yamux "github.com/whyrusleeping/go-smux-yamux"
 )
@@ -20,7 +21,7 @@ import (
 // security protocols.
 var DefaultSecurity = Security(secio.ID, secio.New)
 
-// DefaultMuxer configures libp2p to use the stream connection multiplexers.
+// DefaultMuxers configures libp2p to use the stream connection multiplexers.
 //
 // Use this option when you want to *extend* the set of multiplexers used by
 // libp2p instead of replacing them.
@@ -52,6 +53,23 @@ var RandomIdentity = func(cfg *Config) error {
 	return cfg.Apply(Identity(priv))
 }
 
+// DefaultListenAddrs configures libp2p to use default listen address
+var DefaultListenAddrs = func(cfg *Config) error {
+	defaultIP4ListenAddr, err := multiaddr.NewMultiaddr("/ip4/0.0.0.0/tcp/0")
+	if err != nil {
+		return err
+	}
+
+	defaultIP6ListenAddr, err := multiaddr.NewMultiaddr("/ip6/::/tcp/0")
+	if err != nil {
+		return err
+	}
+	return cfg.Apply(ListenAddrs(
+		defaultIP4ListenAddr,
+		defaultIP6ListenAddr,
+	))
+}
+
 // Complete list of default options and when to fallback on them.
 //
 // Please *DON'T* specify default options any other way. Putting this all here
@@ -60,6 +78,10 @@ var defaults = []struct {
 	fallback func(cfg *Config) bool
 	opt      Option
 }{
+	{
+		fallback: func(cfg *Config) bool { return cfg.Transports == nil && cfg.ListenAddrs == nil },
+		opt:      DefaultListenAddrs,
+	},
 	{
 		fallback: func(cfg *Config) bool { return cfg.Transports == nil },
 		opt:      DefaultTransports,

libp2p_test.go

@@ -3,11 +3,13 @@ package libp2p
 import (
 	"context"
 	"fmt"
+	"regexp"
 	"strings"
 	"testing"
 
 	crypto "github.com/libp2p/go-libp2p-crypto"
 	host "github.com/libp2p/go-libp2p-host"
+	"github.com/libp2p/go-tcp-transport"
 )
 
 func TestNewHost(t *testing.T) {
@@ -39,6 +41,39 @@ func TestInsecure(t *testing.T) {
 	h.Close()
 }
 
+func TestDefaultListenAddrs(t *testing.T) {
+	ctx := context.Background()
+
+	re := regexp.MustCompile("/(ip)[4|6]/((0.0.0.0)|(::))/tcp/")
+
+	// Test 1: Setting the correct listen addresses if userDefined.Transport == nil && userDefined.ListenAddrs == nil
+	h, err := New(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, addr := range h.Network().ListenAddresses() {
+		if re.FindStringSubmatchIndex(addr.String()) == nil {
+			t.Error("expected ip4 or ip6 interface")
+		}
+	}
+
+	h.Close()
+
+	// Test 2: Listen addr should not set if user defined transport is passed.
+	h, err = New(
+		ctx,
+		Transport(tcp.NewTCPTransport),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(h.Network().ListenAddresses()) != 0 {
+		t.Error("expected zero listen addrs as none is set with user defined transport")
+	}
+	h.Close()
+}
+
 func makeRandomHost(t *testing.T, port int) (host.Host, error) {
 	ctx := context.Background()
 	priv, _, err := crypto.GenerateKeyPair(crypto.RSA, 2048)