Add NoDefaultBootstrap and use it and testify in a few tests

dht/dht.go

@@ -38,12 +38,19 @@ type transactionKey struct {
 // ServerConfig allows to set up a  configuration of the `Server` instance
 // to be created with NewServer
 type ServerConfig struct {
-	Addr string // Listen address. Used if Conn is nil.
+	// Listen address. Used if Conn is nil.
+	Addr string
 	Conn net.PacketConn
 	// Don't respond to queries from other nodes.
 	Passive bool
 	// DHT Bootstrap nodes
 	BootstrapNodes []string
+	// Disable bootstrapping from global servers even if given no BootstrapNodes.
+	// This creates a solitary node that awaits other nodes; it's only useful if
+	// you're creating your own DHT and want to avoid accidental crossover, without
+	// spoofing a bootstrap node and filling your logs with connection errors.
+	NoDefaultBootstrap bool
+
 	// Disable the DHT security extension:
 	// http://www.libtorrent.org/dht_sec.html.
 	NoSecurity bool
@@ -171,6 +178,7 @@ func (n *node) DefinitelyGood() bool {
 	}
 	return true
 }
+
 func jitterDuration(average time.Duration, plusMinus time.Duration) time.Duration {
 	return average - plusMinus/2 + time.Duration(rand.Int63n(int64(plusMinus)))
 }

dht/dht_test.go

@@ -107,23 +107,23 @@ func TestDHTDefaultConfig(t *testing.T) {
 }
 
 func TestPing(t *testing.T) {
-	srv, err := NewServer(nil)
-	if err != nil {
-		t.Fatal(err)
-	}
+	srv, err := NewServer(&ServerConfig{
+		Addr:               "127.0.0.1:5680",
+		NoDefaultBootstrap: true,
+	})
+	require.NoError(t, err)
 	defer srv.Close()
-	srv0, err := NewServer(nil)
-	if err != nil {
-		t.Fatal(err)
-	}
+	srv0, err := NewServer(&ServerConfig{
+		Addr:           "127.0.0.1:5681",
+		BootstrapNodes: []string{"127.0.0.1:5680"},
+	})
+	require.NoError(t, err)
 	defer srv0.Close()
 	tn, err := srv.Ping(&net.UDPAddr{
 		IP:   []byte{127, 0, 0, 1},
 		Port: srv0.Addr().(*net.UDPAddr).Port,
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 	defer tn.Close()
 	ok := make(chan bool)
 	tn.SetResponseHandler(func(msg Msg, msgOk bool) {
@@ -159,9 +159,7 @@ func TestDHTSec(t *testing.T) {
 	} {
 		ip := net.ParseIP(case_.ipStr)
 		id, err := hex.DecodeString(case_.nodeIDHex)
-		if err != nil {
-			t.Fatal(err)
-		}
+		require.NoError(t, err)
 		secure := NodeIdSecure(string(id), ip)
 		if secure != case_.valid {
 			t.Fatalf("case failed: %v", case_)

dht/server.go

@@ -541,7 +541,7 @@ func (s *Server) addRootNodes() error {
 func (s *Server) bootstrap() (err error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	if len(s.nodes) == 0 {
+	if len(s.nodes) == 0 && !s.config.NoDefaultBootstrap {
 		err = s.addRootNodes()
 	}
 	if err != nil {