[fix]/debug

[fix]/debug

Former-commit-id: 69c1aaa

.gitignore

@@ -1 +1,2 @@
 ./go-examples
+./rendezvous/chat

README.md

@@ -1 +1,65 @@
-# p2chat 
+# p2chat
+
+Examples of local chats on libp2p stack
+
+Both examples work with automatic peer discovery
+I've separated mdns from rendezvous point, so you can try both of methods as you  wish
+
+
+
+## What's the main difference and how it could be implemented as MoonShard solution
+
+Simply words, both methods use DHT for peerdiscovery
+
+mDNS using micro-dns service, which means that routing node in the network should support
+this service. Most of modern routers should support it, but not everyone
+(i.g. mDNS will definetly not working at Moscow subways as we learned in fields testing)
+Also not sure mDNS will work from mobile ad-hoc points, but have not tested it this far
+
+Rendezvous point is better solution, and also should decrease battery consumption
+Also it should better connect local chats with cloud (remote) nodes.
+Rendezvous also great when thereare a lot of offline nodes behind NAT and it hard to connect with them
+
+Probably will switch to SONM solution, but as far we are fully accomplish with libp2p stack
+
+
+## How to build
+require go version >=1.11 , so make sure your `go version` is okay
+
+If it start yelling about go modules, try
+```
+export GO111MODULE=on
+```
+I've include it into Makefile, but not sure it will work correctly
+
+
+### How to build rendezvous
+From main repo run
+```
+> make deps
+> cd ./rendezvous
+> go build -o chat
+
+```
+### How to use rendezvous
+Use two different terminal windows to run
+```
+./chat -listen /ip4/127.0.0.1/tcp/6666
+./chat -listen /ip4/127.0.0.1/tcp/6668
+
+```
+Remember about NAT penetration!
+
+### How to build mDNS
+```
+go get -v -d ./...
+go build
+```
+
+### How to use mDNS  
+
+Use two different terminal windows to run
+```
+./mDNS -port 6666
+./mDNS -port 6667
+```

mDNS/flags.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"flag"
+)
+
+type config struct {
+	RendezvousString string
+	ProtocolID       string
+	listenHost       string
+	listenPort       int
+}
+
+func parseFlags() *config {
+	c := &config{}
+
+	flag.StringVar(&c.RendezvousString, "rendezvous", "meetme", "Unique string to identify group of nodes. Share this with your friends to let them connect with you")
+	flag.StringVar(&c.listenHost, "host", "0.0.0.0", "The bootstrap node host listen address\n")
+	flag.StringVar(&c.ProtocolID, "pid", "/chat/1.1.0", "Sets a protocol id for stream headers")
+	flag.IntVar(&c.listenPort, "port", 4001, "node listen port")
+
+	flag.Parse()
+	return c
+}

mDNS/main.go

@@ -0,0 +1,140 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"crypto/rand"
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p-crypto"
+	inet "github.com/libp2p/go-libp2p-net"
+	protocol "github.com/libp2p/go-libp2p-protocol"
+	"github.com/multiformats/go-multiaddr"
+)
+
+func handleStream(stream inet.Stream) {
+	fmt.Println("Got a new stream!")
+
+	// Create a buffer stream for non blocking read and write.
+	rw := bufio.NewReadWriter(bufio.NewReader(stream), bufio.NewWriter(stream))
+
+	go readData(rw)
+	go writeData(rw)
+
+	// 'stream' will stay open until you close it (or the other side closes it).
+}
+
+func readData(rw *bufio.ReadWriter) {
+	for {
+		str, err := rw.ReadString('\n')
+		if err != nil {
+			fmt.Println("Error reading from buffer")
+			panic(err)
+		}
+
+		if str == "" {
+			return
+		}
+		if str != "\n" {
+			// Green console colour: 	\x1b[32m
+			// Reset console colour: 	\x1b[0m
+			fmt.Printf("\x1b[32m%s\x1b[0m> ", str)
+		}
+
+	}
+}
+
+func writeData(rw *bufio.ReadWriter) {
+	stdReader := bufio.NewReader(os.Stdin)
+
+	for {
+		fmt.Print("> ")
+		sendData, err := stdReader.ReadString('\n')
+		if err != nil {
+			fmt.Println("Error reading from stdin")
+			panic(err)
+		}
+
+		_, err = rw.WriteString(fmt.Sprintf("%s\n", sendData))
+		if err != nil {
+			fmt.Println("Error writing to buffer")
+			panic(err)
+		}
+		err = rw.Flush()
+		if err != nil {
+			fmt.Println("Error flushing buffer")
+			panic(err)
+		}
+	}
+}
+
+func main() {
+	help := flag.Bool("help", false, "Display Help")
+	cfg := parseFlags()
+
+	if *help {
+		fmt.Printf("Simple example for peer discovery using mDNS. mDNS is great when you have multiple peers in local LAN.")
+		fmt.Printf("Usage: \n   Run './chat-with-mdns'\nor Run './chat-with-mdns -host [host] -port [port] -rendezvous [string] -pid [proto ID]'\n")
+
+		os.Exit(0)
+	}
+
+	fmt.Printf("[*] Listening on: %s with port: %d\n", cfg.listenHost, cfg.listenPort)
+
+	ctx := context.Background()
+	r := rand.Reader
+
+	// Creates a new RSA key pair for this host.
+	prvKey, _, err := crypto.GenerateKeyPairWithReader(crypto.RSA, 2048, r)
+	if err != nil {
+		panic(err)
+	}
+
+	// 0.0.0.0 will listen on any interface device.
+	sourceMultiAddr, _ := multiaddr.NewMultiaddr(fmt.Sprintf("/ip4/%s/tcp/%d", cfg.listenHost, cfg.listenPort))
+
+	// libp2p.New constructs a new libp2p Host.
+	// Other options can be added here.
+	host, err := libp2p.New(
+		ctx,
+		libp2p.ListenAddrs(sourceMultiAddr),
+		libp2p.Identity(prvKey),
+	)
+
+	if err != nil {
+		panic(err)
+	}
+
+	// Set a function as stream handler.
+	// This function is called when a peer initiates a connection and starts a stream with this peer.
+	host.SetStreamHandler(protocol.ID(cfg.ProtocolID), handleStream)
+
+	fmt.Printf("\n[*] Your Multiaddress Is: /ip4/%s/tcp/%v/p2p/%s\n", cfg.listenHost, cfg.listenPort, host.ID().Pretty())
+
+	peerChan := initMDNS(ctx, host, cfg.RendezvousString)
+
+	peer := <-peerChan // will block untill we discover a peer
+	fmt.Println("Found peer:", peer, ", connecting")
+
+	if err := host.Connect(ctx, peer); err != nil {
+		fmt.Println("Connection failed:", err)
+	}
+
+	// open a stream, this stream will be handled by handleStream other end
+	stream, err := host.NewStream(ctx, peer.ID, protocol.ID(cfg.ProtocolID))
+
+	if err != nil {
+		fmt.Println("Stream open failed", err)
+	} else {
+		rw := bufio.NewReadWriter(bufio.NewReader(stream), bufio.NewWriter(stream))
+
+		go writeData(rw)
+		go readData(rw)
+		fmt.Println("Connected to:", peer)
+	}
+
+	select {} //wait here
+}

mDNS/mdns.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"context"
+	"time"
+
+	host "github.com/libp2p/go-libp2p-host"
+	pstore "github.com/libp2p/go-libp2p-peerstore"
+	"github.com/libp2p/go-libp2p/p2p/discovery"
+)
+
+type discoveryNotifee struct {
+	PeerChan chan pstore.PeerInfo
+}
+
+//interface to be called when new  peer is found
+func (n *discoveryNotifee) HandlePeerFound(pi pstore.PeerInfo) {
+	n.PeerChan <- pi
+}
+
+//Initialize the MDNS service
+func initMDNS(ctx context.Context, peerhost host.Host, rendezvous string) chan pstore.PeerInfo {
+	// An hour might be a long long period in practical applications. But this is fine for us
+	ser, err := discovery.NewMdnsService(ctx, peerhost, time.Hour, rendezvous)
+	if err != nil {
+		panic(err)
+	}
+
+	//register with service so that we get notified about peer discovery
+	n := &discoveryNotifee{}
+	n.PeerChan = make(chan pstore.PeerInfo)
+
+	ser.RegisterNotifee(n)
+	return n.PeerChan
+}