functional parameters

examples/echo/main.go

@@ -18,12 +18,8 @@ import (
 	net "github.com/libp2p/go-libp2p-net"
 	peer "github.com/libp2p/go-libp2p-peer"
 	pstore "github.com/libp2p/go-libp2p-peerstore"
-	swarm "github.com/libp2p/go-libp2p-swarm"
-	bhost "github.com/libp2p/go-libp2p/p2p/host/basic"
 	ma "github.com/multiformats/go-multiaddr"
 	gologging "github.com/whyrusleeping/go-logging"
-	msmux "github.com/whyrusleeping/go-smux-multistream"
-	yamux "github.com/whyrusleeping/go-smux-yamux"
 )
 
 // makeBasicHost creates a LibP2P host with a random peer ID listening on the
@@ -42,37 +38,21 @@ func makeBasicHost(listenPort int, secio bool, randseed int64) (host.Host, error
 
 	// Generate a key pair for this host. We will use it at least
 	// to obtain a valid host ID.
-	priv, pub, err := crypto.GenerateKeyPairWithReader(crypto.RSA, 2048, r)
+	priv, _, err := crypto.GenerateKeyPairWithReader(crypto.RSA, 2048, r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Obtain Peer ID from public key
-	pid, err := peer.IDFromPublicKey(pub)
-	if err != nil {
-		return nil, err
-	}
-
-	// Create a multiaddress
-	addr, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", listenPort))
-
-	if err != nil {
-		return nil, err
+	opts := []libp2p.Option{
+		libp2p.ListenAddrStrings(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", listenPort)),
+		libp2p.WithPeerKey(priv),
 	}
 
-	// Create a peerstore
-	ps := pstore.NewPeerstore()
-
-	// If using secio, we add the keys to the peerstore
-	// for this peer ID.
-	if secio {
-		ps.AddPrivKey(pid, priv)
-		ps.AddPubKey(pid, pub)
+	if !secio {
+		opts = append(opts, libp2p.NoSecio)
 	}
 
-	basicHost, err := libp2p.NewWithCfg(ctx, &libp2p.Config{
-		ListenAddrs: []ma.Multiaddr{addr},
-	})
+	basicHost, err := libp2p.New(context.Background(), opts...)
 	if err != nil {
 		return nil, err
 	}
@@ -82,6 +62,7 @@ func makeBasicHost(listenPort int, secio bool, randseed int64) (host.Host, error
 
 	// Now we can build a full multiaddress to reach this host
 	// by encapsulating both addresses:
+	addr := basicHost.Addrs()[0]
 	fullAddr := addr.Encapsulate(hostAddr)
 	log.Printf("I am %s\n", fullAddr)
 	if secio {

examples/libp2p-host/host.go

@@ -7,7 +7,6 @@ import (
 
 	libp2p "github.com/libp2p/go-libp2p"
 	crypto "github.com/libp2p/go-libp2p-crypto"
-	ma "github.com/multiformats/go-multiaddr"
 )
 
 func main() {
@@ -23,27 +22,23 @@ func main() {
 
 	fmt.Printf("Hello World, my hosts ID is %s\n", h.ID())
 
-	// If you want more control over the configuration, you can fill out fields
-	// in the libp2p config, and use `NewWithCfg`
-	cfg := new(libp2p.Config)
+	// If you want more control over the configuration, you can specify some
+	// options to the constructor
 
 	// Set your own keypair
 	priv, _, err := crypto.GenerateEd25519Key(rand.Reader)
 	if err != nil {
 		panic(err)
 	}
-	cfg.PeerKey = priv
 
-	// Set your own listen address
-	maddr, err := ma.NewMultiaddr("/ip4/0.0.0.0/tcp/9000")
-	if err != nil {
-		panic(err)
-	}
-
-	// The config takes an array of addresses, specify as many as you want.
-	cfg.ListenAddrs = []ma.Multiaddr{maddr}
+	h2, err := libp2p.New(ctx,
+		// Use your own created keypair
+		libp2p.WithPeerKey(priv),
 
-	h2, err := libp2p.NewWithCfg(ctx, cfg)
+		// Set your own listen address
+		// The config takes an array of addresses, specify as many as you want.
+		libp2p.ListenAddrStrings("/ip4/0.0.0.0/tcp/9000"),
+	)
 	if err != nil {
 		panic(err)
 	}

libp2p.go

@@ -32,13 +32,88 @@ type Config struct {
 	DisableSecio bool
 }
 
-func New(ctx context.Context) (host.Host, error) {
-	return NewWithCfg(ctx, DefaultConfig())
+type Option func(cfg *Config) error
+
+func Transports(tpts []transport.Transport) Option {
+	return func(cfg *Config) error {
+		cfg.Transports = tpts
+		return nil
+	}
+}
+
+func ListenAddrStrings(s ...string) Option {
+	return func(cfg *Config) error {
+		for _, addrstr := range s {
+			a, err := ma.NewMultiaddr(addrstr)
+			if err != nil {
+				return err
+			}
+			cfg.ListenAddrs = append(cfg.ListenAddrs, a)
+		}
+		return nil
+	}
+}
+
+func ListenAddrs(addrs []ma.Multiaddr) Option {
+	return func(cfg *Config) error {
+		cfg.ListenAddrs = append(cfg.ListenAddrs, addrs...)
+		return nil
+	}
+}
+
+func NoSecio(cfg *Config) error {
+	cfg.DisableSecio = true
+	return nil
+}
+
+func WithMuxer(m mux.Transport) Option {
+	return func(cfg *Config) error {
+		cfg.Muxer = m
+		return nil
+	}
+}
+
+func WithPeerstore(ps pstore.Peerstore) Option {
+	return func(cfg *Config) error {
+		cfg.Peerstore = ps
+		return nil
+	}
+}
+
+func WithNetProtector(prot pnet.Protector) Option {
+	return func(cfg *Config) error {
+		cfg.Protector = prot
+		return nil
+	}
+}
+
+func WithBandwidthReporter(rep metrics.Reporter) Option {
+	return func(cfg *Config) error {
+		cfg.Reporter = rep
+		return nil
+	}
+}
+
+func New(ctx context.Context, opts ...Option) (host.Host, error) {
+	cfg := DefaultConfig()
+
+	for _, opt := range opts {
+		if err := opt(cfg); err != nil {
+			return nil, err
+		}
+	}
+
+	return newWithCfg(ctx, cfg)
+}
+
+func WithPeerKey(sk crypto.PrivKey) Option {
+	return func(cfg *Config) error {
+		cfg.PeerKey = sk
+		return nil
+	}
 }
 
-// Construct instantiates a libp2p host using information from the given
-// config. `nil` may be passed to use default options.
-func NewWithCfg(ctx context.Context, cfg *Config) (host.Host, error) {
+func newWithCfg(ctx context.Context, cfg *Config) (host.Host, error) {
 	if cfg == nil {
 		cfg = DefaultConfig()
 	}