Sensor Network Demo

main.go

package main

import (
	"math/big"
	"os"
	"os/signal"
	"syscall"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/forkid"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/eth/protocols/eth"
	"github.com/ethereum/go-ethereum/p2p"
	"github.com/ethereum/go-ethereum/p2p/enode"
	"github.com/ethereum/go-ethereum/p2p/nat"
	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
)

var protocol = p2p.Protocol{
	Name:    "eth",
	Version: 66,
	Length:  17,
	Run: func(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
		status := eth.StatusPacket{
			ProtocolVersion: 66,
			NetworkID:       137,
			Genesis:         common.HexToHash("0xa9c28ce2141b56c474f1dc504bee9b01eb1bd7d1a507580d5519d4437a97de1b"),
			ForkID:          forkid.ID{Hash: [4]byte{79, 47, 113, 204}},
			Head:            common.HexToHash("0xfd946f1f1b1fd182ee7a4a0d4ed08ba216d555deb4353052d00a6f088d96b740"),
			TD:              big.NewInt(810023945),
		}
		err := p2p.Send(rw, eth.StatusMsg, &status)
		if err != nil {
			return err
		}

		for {
			msg, err := rw.ReadMsg()
			if err != nil {
				return err
			}

			switch msg.Code {
			case eth.StatusMsg:
				var packet eth.StatusPacket
				err = msg.Decode(&packet)
				if err != nil {
					return err
				}
				if packet.NetworkID != status.NetworkID {
					return p2p.DiscRequested
				}
				log.Info().Any("status", packet).Send()
			default:
				log.Info().Any("msg", msg).Send()
			}

			if err = msg.Discard(); err != nil {
				return err
			}
		}
	},
}

func main() {
	log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr})

	privateKey, err := crypto.GenerateKey()
	if err != nil {
		log.Fatal().Err(err).Send()
	}

	server := p2p.Server{
		Config: p2p.Config{
			PrivateKey: privateKey,
			BootstrapNodes: []*enode.Node{
				enode.MustParseV4("enode://b8f1cc9c5d4403703fbf377116469667d2b1823c0daf16b7250aa576bacf399e42c3930ccfcb02c5df6879565a2b8931335565f0e8d3f8e72385ecf4a4bf160a@3.36.224.80:30303"),
				enode.MustParseV4("enode://8729e0c825f3d9cad382555f3e46dcff21af323e89025a0e6312df541f4a9e73abfa562d64906f5e59c51fe6f0501b3e61b07979606c56329c020ed739910759@54.194.245.5:30303"),
			},
			MaxPeers:    10,
			ListenAddr:  ":30303",
			Protocols:   []p2p.Protocol{protocol},
			NAT:         nat.Any(),
			DiscoveryV4: true,
		},
	}

	if err := server.Start(); err != nil {
		log.Fatal().Err(err).Send()
	}
	defer server.Stop()

	events := make(chan *p2p.PeerEvent)
	server.SubscribeEvents(events)

	signals := make(chan os.Signal, 1)
	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)

	for {
		select {
		case event := <-events:
			log.Debug().Any("event", event).Send()
		case <-signals:
			log.Print("Stopping server")
			return
		}
	}
}