p2p: use discovery by default

This makes the zero Config slightly more useful. It also fixes package
node tests because Node detects reuse of the datadir through the
NodeDatabase.

cmd/geth/config.go

@@ -57,10 +57,7 @@ var defaultNodeConfig = node.Config{
 	Name:        clientIdentifier,
 	Version:     params.VersionWithCommit(gitCommit),
 	DataDir:     node.DefaultDataDir(),
-	P2P: p2p.Config{
+	P2P:         p2p.Config{MaxPeers: 25},
-		MaxPeers:  25,
-		Discovery: true,
-	},
 	HTTPModules: []string{"eth", "net", "web3"},
 	WSModules:   []string{"eth", "net", "web3"},
 }

cmd/utils/flags.go

@@ -695,7 +695,7 @@ func SetP2PConfig(ctx *cli.Context, cfg *p2p.Config) {
 		cfg.MaxPendingPeers = ctx.GlobalInt(MaxPendingPeersFlag.Name)
 	}
 	if ctx.GlobalIsSet(NoDiscoverFlag.Name) || ctx.GlobalBool(LightModeFlag.Name) {
-		cfg.Discovery = false
+		cfg.NoDiscovery = true
 	}
 
 	// if we're running a light client or server, force enable the v5 peer discovery
@@ -720,7 +720,7 @@ func SetP2PConfig(ctx *cli.Context, cfg *p2p.Config) {
 		// --dev mode can't use p2p networking.
 		cfg.MaxPeers = 0
 		cfg.ListenAddr = ":0"
-		cfg.Discovery = false
+		cfg.NoDiscovery = true
 		cfg.DiscoveryV5 = false
 	}
 }

cmd/wnode/main.go

@@ -257,7 +257,6 @@ func initialize() {
 		Config: p2p.Config{
 			PrivateKey:     nodeid,
 			MaxPeers:       maxPeers,
-			Discovery:      true,
 			Name:           common.MakeName("wnode", "5.0"),
 			Protocols:      shh.Protocols(),
 			ListenAddr:     *argIP,

mobile/geth.go

@@ -115,7 +115,6 @@ func NewNode(datadir string, config *NodeConfig) (stack *Node, _ error) {
 		DataDir:     datadir,
 		KeyStoreDir: filepath.Join(datadir, "keystore"), // Mobile should never use internal keystores!
 		P2P: p2p.Config{
-			Discovery:        true,
 			DiscoveryV5:      true,
 			DiscoveryV5Addr:  ":0",
 			BootstrapNodesV5: config.BootstrapNodes.nodes,

p2p/server.go

@@ -69,9 +69,9 @@ type Config struct {
 	// Zero defaults to preset values.
 	MaxPendingPeers int `toml:",omitempty"`
 
-	// Discovery specifies whether the peer discovery mechanism should be started
+	// NoDiscowery can be used to disable the peer discovery mechanism.
-	// or not. Disabling is usually useful for protocol debugging (manual topology).
+	// Disabling is useful for protocol debugging (manual topology).
-	Discovery bool
+	NoDiscovery bool
 
 	// DiscoveryV5 specifies whether the the new topic-discovery based V5 discovery
 	// protocol should be started or not.
@@ -370,7 +370,7 @@ func (srv *Server) Start() (err error) {
 	srv.peerOpDone = make(chan struct{})
 
 	// node table
-	if srv.Discovery {
+	if !srv.NoDiscovery {
 		ntab, err := discover.ListenUDP(srv.PrivateKey, srv.ListenAddr, srv.NAT, srv.NodeDatabase, srv.NetRestrict)
 		if err != nil {
 			return err
@@ -393,7 +393,7 @@ func (srv *Server) Start() (err error) {
 	}
 
 	dynPeers := (srv.MaxPeers + 1) / 2
-	if !srv.Discovery {
+	if srv.NoDiscovery {
 		dynPeers = 0
 	}
 	dialer := newDialState(srv.StaticNodes, srv.BootstrapNodes, srv.ntab, dynPeers, srv.NetRestrict)