Merge pull request #1239 from libp2p/autorelay-options

pass static relays to EnableAutoRelay, deprecate libp2p.StaticRelays and libp2p.DefaultStaticRelays

config/config.go

@@ -97,7 +97,7 @@ type Config struct {
 
 	EnableAutoRelay bool
 	AutoNATConfig
-	StaticRelays []peer.AddrInfo
+	StaticRelayOpt autorelay.StaticRelayOption
 
 	EnableHolePunching  bool
 	HolePunchingOptions []holepunch.Option
@@ -251,8 +251,9 @@ func (cfg *Config) NewNode() (host.Host, error) {
 			return nil, fmt.Errorf("cannot enable autorelay; relay is not enabled")
 		}
 
-		if len(cfg.StaticRelays) > 0 {
-			ar = autorelay.NewAutoRelay(h, nil, router, cfg.StaticRelays)
+		var opts []autorelay.Option
+		if cfg.StaticRelayOpt != nil {
+			opts = append(opts, autorelay.Option(cfg.StaticRelayOpt))
 		} else {
 			if router == nil {
 				h.Close()
@@ -263,9 +264,11 @@ func (cfg *Config) NewNode() (host.Host, error) {
 				h.Close()
 				return nil, fmt.Errorf("cannot enable autorelay; no suitable routing for discovery")
 			}
-
-			discovery := discovery.NewRoutingDiscovery(crouter)
-			ar = autorelay.NewAutoRelay(h, discovery, router, cfg.StaticRelays)
+			opts = append(opts, autorelay.WithDiscoverer(discovery.NewRoutingDiscovery(crouter)))
+		}
+		ar, err = autorelay.NewAutoRelay(h, router, opts...)
+		if err != nil {
+			return nil, err
 		}
 	}
 

options.go

@@ -250,8 +250,14 @@ func EnableRelayService(opts ...relayv2.Option) Option {
 //
 // This subsystem performs automatic address rewriting to advertise relay addresses when it
 // detects that the node is publicly unreachable (e.g. behind a NAT).
-func EnableAutoRelay() Option {
+func EnableAutoRelay(opts ...autorelay.StaticRelayOption) Option {
 	return func(cfg *Config) error {
+		if len(opts) > 0 {
+			if len(opts) > 1 {
+				return errors.New("only expected a single static relay configuration option")
+			}
+			cfg.StaticRelayOpt = opts[0]
+		}
 		cfg.EnableAutoRelay = true
 		return nil
 	}
@@ -260,30 +266,26 @@ func EnableAutoRelay() Option {
 // StaticRelays configures known relays for autorelay; when this option is enabled
 // then the system will use the configured relays instead of querying the DHT to
 // discover relays.
+// Deprecated: pass an autorelay.WithStaticRelays option to EnableAutoRelay.
 func StaticRelays(relays []peer.AddrInfo) Option {
 	return func(cfg *Config) error {
-		cfg.StaticRelays = append(cfg.StaticRelays, relays...)
+		cfg.StaticRelayOpt = autorelay.WithStaticRelays(relays)
 		return nil
 	}
 }
 
 // DefaultStaticRelays configures the static relays to use the known PL-operated relays.
+// Deprecated: pass autorelay.WithDefaultStaticRelays to EnableAutoRelay.
 func DefaultStaticRelays() Option {
-	return func(cfg *Config) error {
-		for _, addr := range autorelay.DefaultRelays {
-			a, err := ma.NewMultiaddr(addr)
-			if err != nil {
-				return err
-			}
-			pi, err := peer.AddrInfoFromP2pAddr(a)
-			if err != nil {
-				return err
-			}
-			cfg.StaticRelays = append(cfg.StaticRelays, *pi)
+	relays := make([]peer.AddrInfo, 0, len(autorelay.DefaultRelays))
+	for _, addr := range autorelay.DefaultRelays {
+		pi, err := peer.AddrInfoFromString(addr)
+		if err != nil {
+			panic(fmt.Sprintf("failed to initialize default static relays: %s", err))
 		}
-
-		return nil
+		relays = append(relays, *pi)
 	}
+	return StaticRelays(relays)
 }
 
 // ForceReachabilityPublic overrides automatic reachability detection in the AutoNAT subsystem,

p2p/host/autorelay/autorelay.go

@@ -2,6 +2,7 @@ package autorelay
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"math/rand"
 	"sync"
@@ -42,7 +43,7 @@ var (
 	BootDelay = 20 * time.Second
 )
 
-// These are the known PL-operated v1 relays; will be decommissioned in 2022.
+// DefaultRelays are the known PL-operated v1 relays; will be decommissioned in 2022.
 var DefaultRelays = []string{
 	"/ip4/147.75.80.110/tcp/4001/p2p/QmbFgm5zan8P6eWWmeyfncR5feYEMPbht5b1FW1C37aQ7y",
 	"/ip4/147.75.80.110/udp/4001/quic/p2p/QmbFgm5zan8P6eWWmeyfncR5feYEMPbht5b1FW1C37aQ7y",
@@ -52,6 +53,42 @@ var DefaultRelays = []string{
 	"/ip4/147.75.70.221/udp/4001/quic/p2p/Qme8g49gm3q4Acp7xWBKg3nAa9fxZ1YmyDJdyGgoG6LsXh",
 }
 
+var defaultStaticRelays []peer.AddrInfo
+
+func init() {
+	for _, s := range DefaultRelays {
+		pi, err := peer.AddrInfoFromString(s)
+		if err != nil {
+			panic(fmt.Sprintf("failed to initialize default static relays: %s", err))
+		}
+		defaultStaticRelays = append(defaultStaticRelays, *pi)
+	}
+}
+
+type Option func(*AutoRelay) error
+type StaticRelayOption Option
+
+func WithStaticRelays(static []peer.AddrInfo) StaticRelayOption {
+	return func(r *AutoRelay) error {
+		if len(r.static) > 0 {
+			return errors.New("can't set static relays, static relays already configured")
+		}
+		r.static = static
+		return nil
+	}
+}
+
+func WithDefaultStaticRelays() StaticRelayOption {
+	return WithStaticRelays(defaultStaticRelays)
+}
+
+func WithDiscoverer(discover discovery.Discoverer) Option {
+	return func(r *AutoRelay) error {
+		r.discover = discover
+		return nil
+	}
+}
+
 // AutoRelay is a Host that uses relays for connectivity when a NAT is detected.
 type AutoRelay struct {
 	host     *basic.BasicHost
@@ -74,24 +111,27 @@ type AutoRelay struct {
 	cachedAddrsExpiry time.Time
 }
 
-func NewAutoRelay(bhost *basic.BasicHost, discover discovery.Discoverer, router routing.PeerRouting, static []peer.AddrInfo) *AutoRelay {
+func NewAutoRelay(bhost *basic.BasicHost, router routing.PeerRouting, opts ...Option) (*AutoRelay, error) {
 	ctx, cancel := context.WithCancel(context.Background())
 	ar := &AutoRelay{
 		ctxCancel:  cancel,
 		host:       bhost,
-		discover:   discover,
 		router:     router,
 		addrsF:     bhost.AddrsFactory,
-		static:     static,
 		relays:     make(map[peer.ID]*circuitv2.Reservation),
 		disconnect: make(chan struct{}, 1),
 		status:     network.ReachabilityUnknown,
 	}
+	for _, opt := range opts {
+		if err := opt(ar); err != nil {
+			return nil, err
+		}
+	}
 	bhost.AddrsFactory = ar.hostAddrs
 	bhost.Network().Notify(ar)
 	ar.refCount.Add(1)
 	go ar.background(ctx)
-	return ar
+	return ar, nil
 }
 
 func (ar *AutoRelay) hostAddrs(addrs []ma.Multiaddr) []ma.Multiaddr {