Add libp2p example

examples/README.md

@@ -1,69 +1,6 @@
 examples
 ===
 
-## Go
+This folder contains the following examples of using the webrtc-direct transport:
-This folder contains an example go app that connects using go-libp2p-webrtc-direct. It can be used as follows:
+1. [standalone](./standalone): This example shows how you can use the go-libp2p-webrtc-direct transport on its own.
-
+1. [libp2p-echo](./libp2p-echo): This example is a variant of the [libp2p echo](https://github.com/libp2p/go-libp2p-examples/blob/master/echo) example. It shows how the webrtc-direct transport can be plugged into libp2p.
-### Install dependencies
-**TODO**: Check the root readme
-
-### Listener
-```sh
-go run main.go -listen
-```
-*Output*
-```
-[listener] Listening
-[listener] Got connection
-[listener] Got stream
-[listener] Received:
-hey, how is it going. I am the dialer
-Failed to accept data channel: The association is closed
-```
-The last line is harmless warning printed by the pions/webrtc library.
-### Dialer
-```sh
-go run main.go
-```
-*Output*
-```
-Warning: Certificate not checked
-[dialer] Opened connection
-[dialer] Opened stream
-Failed to push SCTP packet: Failed sending reply: dtls: conn is closed
-Warning: mux: no endpoint for packet starting with 23
-Failed to push SCTP packet: Failed sending reply: dtls: conn is closed
-Warning: mux: no endpoint for packet starting with 21
-Failed to accept data channel: The association is closed
-```
-The warnings printed by the pions/webrtc library are harmless.
-
-## Javascript
-The equivalent javascript example is also provided. It can be used as follows:
-
-### Install dependencies
-```sh
-npm install
-```
-
-### Listener
-```sh
-node index.js --listen
-```
-*Output*
-```
-[listener] Listening
-[listener] Got connection
-[listener] Got stream
-[listener] Received:
-hey, how is it going. I am the dialer
-```
-### Dialer
-```sh
-node index.js
-```
-*Output*
-```
-[dialer] Opened connection
-[dialer] Opened stream
-```

examples/libp2p-echo/README.md

@@ -0,0 +1,4 @@
+libp2p-echo
+===
+
+This example is a variant of the [libp2p echo](https://github.com/libp2p/go-libp2p-examples/blob/master/echo) example. It shows how the webrtc-direct transport can be plugged into libp2p.

examples/libp2p-echo/main.go

@@ -0,0 +1,189 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"crypto/rand"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	mrand "math/rand"
+
+	golog "github.com/ipfs/go-log"
+	libp2p "github.com/libp2p/go-libp2p"
+	crypto "github.com/libp2p/go-libp2p-crypto"
+	host "github.com/libp2p/go-libp2p-host"
+	net "github.com/libp2p/go-libp2p-net"
+	peer "github.com/libp2p/go-libp2p-peer"
+	pstore "github.com/libp2p/go-libp2p-peerstore"
+	ma "github.com/multiformats/go-multiaddr"
+	gologging "github.com/whyrusleeping/go-logging"
+
+	direct "github.com/libp2p/go-libp2p-webrtc-direct"
+	"github.com/pions/webrtc"
+	mplex "github.com/whyrusleeping/go-smux-multiplex"
+)
+
+// makeBasicHost creates a LibP2P host with a random peer ID listening on the
+// given multiaddress. It won't encrypt the connection if insecure is true.
+func makeBasicHost(listenPort int, insecure bool, randseed int64) (host.Host, error) {
+
+	// If the seed is zero, use real cryptographic randomness. Otherwise, use a
+	// deterministic randomness source to make generated keys stay the same
+	// across multiple runs
+	var r io.Reader
+	if randseed == 0 {
+		r = rand.Reader
+	} else {
+		r = mrand.New(mrand.NewSource(randseed))
+	}
+
+	// Generate a key pair for this host. We will use it at least
+	// to obtain a valid host ID.
+	priv, _, err := crypto.GenerateKeyPairWithReader(crypto.RSA, 2048, r)
+	if err != nil {
+		return nil, err
+	}
+
+	transport := direct.NewTransport(
+		webrtc.Configuration{},
+		new(mplex.Transport),
+	)
+
+	opts := []libp2p.Option{
+		libp2p.ListenAddrStrings(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d/http/p2p-webrtc-direct", listenPort)),
+		libp2p.Identity(priv),
+		libp2p.DisableRelay(),
+		libp2p.Transport(transport),
+	}
+
+	if insecure {
+		opts = append(opts, libp2p.NoSecurity)
+	}
+
+	basicHost, err := libp2p.New(context.Background(), opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	// Build host multiaddress
+	hostAddr, _ := ma.NewMultiaddr(fmt.Sprintf("/ipfs/%s", basicHost.ID().Pretty()))
+
+	// 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 insecure {
+		log.Printf("Now run \"./libp2p-echo -l %d -d %s -insecure\" on a different terminal\n", listenPort+1, fullAddr)
+	} else {
+		log.Printf("Now run \"./libp2p-echo -l %d -d %s\" on a different terminal\n", listenPort+1, fullAddr)
+	}
+
+	return basicHost, nil
+}
+
+func main() {
+	// LibP2P code uses golog to log messages. They log with different
+	// string IDs (i.e. "swarm"). We can control the verbosity level for
+	// all loggers with:
+	golog.SetAllLoggers(gologging.INFO) // Change to DEBUG for extra info
+
+	// Parse options from the command line
+	listenF := flag.Int("l", 0, "wait for incoming connections")
+	target := flag.String("d", "", "target peer to dial")
+	insecure := flag.Bool("insecure", false, "use an unencrypted connection")
+	seed := flag.Int64("seed", 0, "set random seed for id generation")
+	flag.Parse()
+
+	if *listenF == 0 {
+		log.Fatal("Please provide a port to bind on with -l")
+	}
+
+	// Make a host that listens on the given multiaddress
+	ha, err := makeBasicHost(*listenF, *insecure, *seed)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Set a stream handler on host A. /echo/1.0.0 is
+	// a user-defined protocol name.
+	ha.SetStreamHandler("/echo/1.0.0", func(s net.Stream) {
+		log.Println("Got a new stream!")
+		if err := doEcho(s); err != nil {
+			log.Println(err)
+			s.Reset()
+		} else {
+			s.Close()
+		}
+	})
+
+	if *target == "" {
+		log.Println("listening for connections")
+		select {} // hang forever
+	}
+	/**** This is where the listener code ends ****/
+
+	// The following code extracts target's the peer ID from the
+	// given multiaddress
+	ipfsaddr, err := ma.NewMultiaddr(*target)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	pid, err := ipfsaddr.ValueForProtocol(ma.P_IPFS)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	peerid, err := peer.IDB58Decode(pid)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	// Decapsulate the /ipfs/<peerID> part from the target
+	// /ip4/<a.b.c.d>/ipfs/<peer> becomes /ip4/<a.b.c.d>
+	targetPeerAddr, _ := ma.NewMultiaddr(
+		fmt.Sprintf("/ipfs/%s", peer.IDB58Encode(peerid)))
+	targetAddr := ipfsaddr.Decapsulate(targetPeerAddr)
+
+	// We have a peer ID and a targetAddr so we add it to the peerstore
+	// so LibP2P knows how to contact it
+	ha.Peerstore().AddAddr(peerid, targetAddr, pstore.PermanentAddrTTL)
+
+	log.Println("opening stream")
+	// make a new stream from host B to host A
+	// it should be handled on host A by the handler we set above because
+	// we use the same /echo/1.0.0 protocol
+	s, err := ha.NewStream(context.Background(), peerid, "/echo/1.0.0")
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	_, err = s.Write([]byte("Hello, world!\n"))
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	out, err := ioutil.ReadAll(s)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	log.Printf("read reply: %q\n", out)
+}
+
+// doEcho reads a line of data a stream and writes it back
+func doEcho(s net.Stream) error {
+	buf := bufio.NewReader(s)
+	str, err := buf.ReadString('\n')
+	if err != nil {
+		return err
+	}
+
+	log.Printf("read: %s\n", str)
+	_, err = s.Write([]byte(str))
+	return err
+}

examples/standalone/README.md

@@ -0,0 +1,70 @@
+standalone
+===
+
+This example shows the transport being used on its own. It also shows off compatibility with [js-libp2p-webrtc-direct](https://github.com/libp2p/js-libp2p-webrtc-direct).
+
+## Go
+
+### Install dependencies
+**TODO**: Check the root readme
+
+### Listener
+```sh
+go run main.go -listen
+```
+*Output*
+```
+[listener] Listening
+[listener] Got connection
+[listener] Got stream
+[listener] Received:
+hey, how is it going. I am the dialer
+Failed to accept data channel: The association is closed
+```
+The last line is harmless warning printed by the pions/webrtc library.
+### Dialer
+```sh
+go run main.go
+```
+*Output*
+```
+Warning: Certificate not checked
+[dialer] Opened connection
+[dialer] Opened stream
+Failed to push SCTP packet: Failed sending reply: dtls: conn is closed
+Warning: mux: no endpoint for packet starting with 23
+Failed to push SCTP packet: Failed sending reply: dtls: conn is closed
+Warning: mux: no endpoint for packet starting with 21
+Failed to accept data channel: The association is closed
+```
+The warnings printed by the pions/webrtc library are harmless.
+
+## Javascript
+The equivalent javascript example is also provided. It can be used as follows:
+
+### Install dependencies
+```sh
+npm install
+```
+
+### Listener
+```sh
+node index.js --listen
+```
+*Output*
+```
+[listener] Listening
+[listener] Got connection
+[listener] Got stream
+[listener] Received:
+hey, how is it going. I am the dialer
+```
+### Dialer
+```sh
+node index.js
+```
+*Output*
+```
+[dialer] Opened connection
+[dialer] Opened stream
+```