ceremonyclient/go-libp2p/examples/chat-with-rendezvous/chat.go

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2023-08-21 03:50:38 +00:00
package main
import (
"bufio"
"context"
"flag"
"fmt"
"os"
"sync"
"github.com/libp2p/go-libp2p"
"github.com/libp2p/go-libp2p/core/network"
"github.com/libp2p/go-libp2p/core/peer"
"github.com/libp2p/go-libp2p/core/protocol"
drouting "github.com/libp2p/go-libp2p/p2p/discovery/routing"
dutil "github.com/libp2p/go-libp2p/p2p/discovery/util"
dht "github.com/libp2p/go-libp2p-kad-dht"
"github.com/multiformats/go-multiaddr"
"github.com/ipfs/go-log/v2"
)
var logger = log.Logger("rendezvous")
func handleStream(stream network.Stream) {
logger.Info("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() {
log.SetAllLoggers(log.LevelWarn)
log.SetLogLevel("rendezvous", "info")
help := flag.Bool("h", false, "Display Help")
config, err := ParseFlags()
if err != nil {
panic(err)
}
if *help {
fmt.Println("This program demonstrates a simple p2p chat application using libp2p")
fmt.Println()
fmt.Println("Usage: Run './chat in two different terminals. Let them connect to the bootstrap nodes, announce themselves and connect to the peers")
flag.PrintDefaults()
return
}
// libp2p.New constructs a new libp2p Host. Other options can be added
// here.
host, err := libp2p.New(libp2p.ListenAddrs([]multiaddr.Multiaddr(config.ListenAddresses)...))
if err != nil {
panic(err)
}
logger.Info("Host created. We are:", host.ID())
logger.Info(host.Addrs())
// 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(config.ProtocolID), handleStream)
// Start a DHT, for use in peer discovery. We can't just make a new DHT
// client because we want each peer to maintain its own local copy of the
// DHT, so that the bootstrapping node of the DHT can go down without
// inhibiting future peer discovery.
ctx := context.Background()
kademliaDHT, err := dht.New(ctx, host)
if err != nil {
panic(err)
}
// Bootstrap the DHT. In the default configuration, this spawns a Background
// thread that will refresh the peer table every five minutes.
logger.Debug("Bootstrapping the DHT")
if err = kademliaDHT.Bootstrap(ctx); err != nil {
panic(err)
}
// Let's connect to the bootstrap nodes first. They will tell us about the
// other nodes in the network.
var wg sync.WaitGroup
for _, peerAddr := range config.BootstrapPeers {
peerinfo, _ := peer.AddrInfoFromP2pAddr(peerAddr)
wg.Add(1)
go func() {
defer wg.Done()
if err := host.Connect(ctx, *peerinfo); err != nil {
logger.Warning(err)
} else {
logger.Info("Connection established with bootstrap node:", *peerinfo)
}
}()
}
wg.Wait()
// We use a rendezvous point "meet me here" to announce our location.
// This is like telling your friends to meet you at the Eiffel Tower.
logger.Info("Announcing ourselves...")
routingDiscovery := drouting.NewRoutingDiscovery(kademliaDHT)
dutil.Advertise(ctx, routingDiscovery, config.RendezvousString)
logger.Debug("Successfully announced!")
// Now, look for others who have announced
// This is like your friend telling you the location to meet you.
logger.Debug("Searching for other peers...")
peerChan, err := routingDiscovery.FindPeers(ctx, config.RendezvousString)
if err != nil {
panic(err)
}
for peer := range peerChan {
if peer.ID == host.ID() {
continue
}
logger.Debug("Found peer:", peer)
logger.Debug("Connecting to:", peer)
stream, err := host.NewStream(ctx, peer.ID, protocol.ID(config.ProtocolID))
if err != nil {
logger.Warning("Connection failed:", err)
continue
} else {
rw := bufio.NewReadWriter(bufio.NewReader(stream), bufio.NewWriter(stream))
go writeData(rw)
go readData(rw)
}
logger.Info("Connected to:", peer)
}
select {}
}