cmd/puppeth: your Ethereum private network manager (#13854)

1 files changed, 456 insertions, 0 deletions

diff --git a/cmd/faucet/faucet.go b/cmd/faucet/faucet.go
new file mode 100644
index 000000000..232f0ff9e
--- /dev/null
+++ b/cmd/faucet/faucet.go
@@ -0,0 +1,456 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+// faucet is a Ether faucet backed by a light client.
+package main
+
+//go:generate go-bindata -nometadata -o website.go faucet.html
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"html/template"
+	"io/ioutil"
+	"math/big"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/ethstats"
+	"github.com/ethereum/go-ethereum/les"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/discv5"
+	"github.com/ethereum/go-ethereum/p2p/nat"
+	"github.com/ethereum/go-ethereum/params"
+	"golang.org/x/net/websocket"
+)
+
+var (
+	genesisFlag = flag.String("genesis", "", "Genesis json file to seed the chain with")
+	apiPortFlag = flag.Int("apiport", 8080, "Listener port for the HTTP API connection")
+	ethPortFlag = flag.Int("ethport", 30303, "Listener port for the devp2p connection")
+	bootFlag    = flag.String("bootnodes", "", "Comma separated bootnode enode URLs to seed with")
+	netFlag     = flag.Int("network", 0, "Network ID to use for the Ethereum protocol")
+	statsFlag   = flag.String("ethstats", "", "Ethstats network monitoring auth string")
+
+	netnameFlag = flag.String("faucet.name", "", "Network name to assign to the faucet")
+	payoutFlag  = flag.Int("faucet.amount", 1, "Number of Ethers to pay out per user request")
+	minutesFlag = flag.Int("faucet.minutes", 1440, "Number of minutes to wait between funding rounds")
+
+	accJSONFlag = flag.String("account.json", "", "Key json file to fund user requests with")
+	accPassFlag = flag.String("account.pass", "", "Decryption password to access faucet funds")
+
+	githubUser  = flag.String("github.user", "", "GitHub user to authenticate with for Gist access")
+	githubToken = flag.String("github.token", "", "GitHub personal token to access Gists with")
+
+	logFlag = flag.Int("loglevel", 3, "Log level to use for Ethereum and the faucet")
+)
+
+var (
+	ether = new(big.Int).Exp(big.NewInt(10), big.NewInt(18), nil)
+)
+
+func main() {
+	// Parse the flags and set up the logger to print everything requested
+	flag.Parse()
+	log.Root().SetHandler(log.LvlFilterHandler(log.Lvl(*logFlag), log.StreamHandler(os.Stderr, log.TerminalFormat(true))))
+
+	// Load up and render the faucet website
+	tmpl, err := Asset("faucet.html")
+	if err != nil {
+		log.Crit("Failed to load the faucet template", "err", err)
+	}
+	period := fmt.Sprintf("%d minute(s)", *minutesFlag)
+	if *minutesFlag%60 == 0 {
+		period = fmt.Sprintf("%d hour(s)", *minutesFlag/60)
+	}
+	website := new(bytes.Buffer)
+	template.Must(template.New("").Parse(string(tmpl))).Execute(website, map[string]interface{}{
+		"Network": *netnameFlag,
+		"Amount":  *payoutFlag,
+		"Period":  period,
+	})
+	// Load and parse the genesis block requested by the user
+	blob, err := ioutil.ReadFile(*genesisFlag)
+	if err != nil {
+		log.Crit("Failed to read genesis block contents", "genesis", *genesisFlag, "err", err)
+	}
+	genesis := new(core.Genesis)
+	if err = json.Unmarshal(blob, genesis); err != nil {
+		log.Crit("Failed to parse genesis block json", "err", err)
+	}
+	// Convert the bootnodes to internal enode representations
+	var enodes []*discv5.Node
+	for _, boot := range strings.Split(*bootFlag, ",") {
+		if url, err := discv5.ParseNode(boot); err == nil {
+			enodes = append(enodes, url)
+		} else {
+			log.Error("Failed to parse bootnode URL", "url", boot, "err", err)
+		}
+	}
+	// Load up the account key and decrypt its password
+	if blob, err = ioutil.ReadFile(*accPassFlag); err != nil {
+		log.Crit("Failed to read account password contents", "file", *accPassFlag, "err", err)
+	}
+	pass := string(blob)
+
+	ks := keystore.NewKeyStore(filepath.Join(os.Getenv("HOME"), ".faucet", "keys"), keystore.StandardScryptN, keystore.StandardScryptP)
+	if blob, err = ioutil.ReadFile(*accJSONFlag); err != nil {
+		log.Crit("Failed to read account key contents", "file", *accJSONFlag, "err", err)
+	}
+	acc, err := ks.Import(blob, pass, pass)
+	if err != nil {
+		log.Crit("Failed to import faucet signer account", "err", err)
+	}
+	ks.Unlock(acc, pass)
+
+	// Assemble and start the faucet light service
+	faucet, err := newFaucet(genesis, *ethPortFlag, enodes, *netFlag, *statsFlag, ks, website.Bytes())
+	if err != nil {
+		log.Crit("Failed to start faucet", "err", err)
+	}
+	defer faucet.close()
+
+	if err := faucet.listenAndServe(*apiPortFlag); err != nil {
+		log.Crit("Failed to launch faucet API", "err", err)
+	}
+}
+
+// request represents an accepted funding request.
+type request struct {
+	Username string             `json:"username"` // GitHub user for displaying an avatar
+	Account  common.Address     `json:"account"`  // Ethereum address being funded
+	Time     time.Time          `json:"time"`     // Timestamp when te request was accepted
+	Tx       *types.Transaction `json:"tx"`       // Transaction funding the account
+}
+
+// faucet represents a crypto faucet backed by an Ethereum light client.
+type faucet struct {
+	config *params.ChainConfig // Chain configurations for signing
+	stack  *node.Node          // Ethereum protocol stack
+	client *ethclient.Client   // Client connection to the Ethereum chain
+	index  []byte              // Index page to serve up on the web
+
+	keystore *keystore.KeyStore // Keystore containing the single signer
+	account  accounts.Account   // Account funding user faucet requests
+	nonce    uint64             // Current pending nonce of the faucet
+	price    *big.Int           // Current gas price to issue funds with
+
+	conns   []*websocket.Conn    // Currently live websocket connections
+	history map[string]time.Time // History of users and their funding requests
+	reqs    []*request           // Currently pending funding requests
+	update  chan struct{}        // Channel to signal request updates
+
+	lock sync.RWMutex // Lock protecting the faucet's internals
+}
+
+func newFaucet(genesis *core.Genesis, port int, enodes []*discv5.Node, network int, stats string, ks *keystore.KeyStore, index []byte) (*faucet, error) {
+	// Assemble the raw devp2p protocol stack
+	stack, err := node.New(&node.Config{
+		Name:             "geth",
+		Version:          params.Version,
+		DataDir:          filepath.Join(os.Getenv("HOME"), ".faucet"),
+		NAT:              nat.Any(),
+		DiscoveryV5:      true,
+		ListenAddr:       fmt.Sprintf(":%d", port),
+		DiscoveryV5Addr:  fmt.Sprintf(":%d", port+1),
+		MaxPeers:         25,
+		BootstrapNodesV5: enodes,
+	})
+	if err != nil {
+		return nil, err
+	}
+	// Assemble the Ethereum light client protocol
+	if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
+		return les.New(ctx, &eth.Config{
+			LightMode:          true,
+			NetworkId:          network,
+			Genesis:            genesis,
+			GasPrice:           big.NewInt(20 * params.Shannon),
+			GpoBlocks:          10,
+			GpoPercentile:      50,
+			EthashCacheDir:     "ethash",
+			EthashCachesInMem:  2,
+			EthashCachesOnDisk: 3,
+		})
+	}); err != nil {
+		return nil, err
+	}
+	// Assemble the ethstats monitoring and reporting service'
+	if stats != "" {
+		if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
+			var serv *les.LightEthereum
+			ctx.Service(&serv)
+			return ethstats.New(stats, nil, serv)
+		}); err != nil {
+			return nil, err
+		}
+	}
+	// Boot up the client and ensure it connects to bootnodes
+	if err := stack.Start(); err != nil {
+		return nil, err
+	}
+	for _, boot := range enodes {
+		old, _ := discover.ParseNode(boot.String())
+		stack.Server().AddPeer(old)
+	}
+	// Attach to the client and retrieve and interesting metadatas
+	api, err := stack.Attach()
+	if err != nil {
+		stack.Stop()
+		return nil, err
+	}
+	client := ethclient.NewClient(api)
+
+	return &faucet{
+		config:   genesis.Config,
+		stack:    stack,
+		client:   client,
+		index:    index,
+		keystore: ks,
+		account:  ks.Accounts()[0],
+		history:  make(map[string]time.Time),
+		update:   make(chan struct{}, 1),
+	}, nil
+}
+
+// close terminates the Ethereum connection and tears down the faucet.
+func (f *faucet) close() error {
+	return f.stack.Stop()
+}
+
+// listenAndServe registers the HTTP handlers for the faucet and boots it up
+// for service user funding requests.
+func (f *faucet) listenAndServe(port int) error {
+	go f.loop()
+
+	http.HandleFunc("/", f.webHandler)
+	http.Handle("/api", websocket.Handler(f.apiHandler))
+
+	return http.ListenAndServe(fmt.Sprintf(":%d", port), nil)
+}
+
+// webHandler handles all non-api requests, simply flattening and returning the
+// faucet website.
+func (f *faucet) webHandler(w http.ResponseWriter, r *http.Request) {
+	w.Write(f.index)
+}
+
+// apiHandler handles requests for Ether grants and transaction statuses.
+func (f *faucet) apiHandler(conn *websocket.Conn) {
+	// Start tracking the connection and drop at the end
+	f.lock.Lock()
+	f.conns = append(f.conns, conn)
+	f.lock.Unlock()
+
+	defer func() {
+		f.lock.Lock()
+		for i, c := range f.conns {
+			if c == conn {
+				f.conns = append(f.conns[:i], f.conns[i+1:]...)
+				break
+			}
+		}
+		f.lock.Unlock()
+	}()
+	// Send a few initial stats to the client
+	balance, _ := f.client.BalanceAt(context.Background(), f.account.Address, nil)
+	nonce, _ := f.client.NonceAt(context.Background(), f.account.Address, nil)
+
+	websocket.JSON.Send(conn, map[string]interface{}{
+		"funds":    balance.Div(balance, ether),
+		"funded":   nonce,
+		"peers":    f.stack.Server().PeerCount(),
+		"requests": f.reqs,
+	})
+	header, _ := f.client.HeaderByNumber(context.Background(), nil)
+	websocket.JSON.Send(conn, header)
+
+	// Keep reading requests from the websocket until the connection breaks
+	for {
+		// Fetch the next funding request and validate against github
+		var msg struct {
+			URL string `json:"url"`
+		}
+		if err := websocket.JSON.Receive(conn, &msg); err != nil {
+			return
+		}
+		if !strings.HasPrefix(msg.URL, "https://gist.github.com/") {
+			websocket.JSON.Send(conn, map[string]string{"error": "URL doesn't link to GitHub Gists"})
+			continue
+		}
+		log.Info("Faucet funds requested", "gist", msg.URL)
+
+		// Retrieve the gist from the GitHub Gist APIs
+		parts := strings.Split(msg.URL, "/")
+		req, _ := http.NewRequest("GET", "https://api.github.com/gists/"+parts[len(parts)-1], nil)
+		if *githubUser != "" {
+			req.SetBasicAuth(*githubUser, *githubToken)
+		}
+		res, err := http.DefaultClient.Do(req)
+		if err != nil {
+			websocket.JSON.Send(conn, map[string]string{"error": err.Error()})
+			continue
+		}
+		var gist struct {
+			Owner struct {
+				Login string `json:"login"`
+			} `json:"owner"`
+			Files map[string]struct {
+				Content string `json:"content"`
+			} `json:"files"`
+		}
+		err = json.NewDecoder(res.Body).Decode(&gist)
+		res.Body.Close()
+		if err != nil {
+			websocket.JSON.Send(conn, map[string]string{"error": err.Error()})
+			continue
+		}
+		if gist.Owner.Login == "" {
+			websocket.JSON.Send(conn, map[string]string{"error": "Nice try ;)"})
+			continue
+		}
+		// Iterate over all the files and look for Ethereum addresses
+		var address common.Address
+		for _, file := range gist.Files {
+			if len(file.Content) == 2+common.AddressLength*2 {
+				address = common.HexToAddress(file.Content)
+			}
+		}
+		if address == (common.Address{}) {
+			websocket.JSON.Send(conn, map[string]string{"error": "No Ethereum address found to fund"})
+			continue
+		}
+		// Ensure the user didn't request funds too recently
+		f.lock.Lock()
+		var (
+			fund    bool
+			elapsed time.Duration
+		)
+		if elapsed = time.Since(f.history[gist.Owner.Login]); elapsed > time.Duration(*minutesFlag)*time.Minute {
+			// User wasn't funded recently, create the funding transaction
+			tx := types.NewTransaction(f.nonce+uint64(len(f.reqs)), address, new(big.Int).Mul(big.NewInt(int64(*payoutFlag)), ether), big.NewInt(21000), f.price, nil)
+			signed, err := f.keystore.SignTx(f.account, tx, f.config.ChainId)
+			if err != nil {
+				websocket.JSON.Send(conn, map[string]string{"error": err.Error()})
+				f.lock.Unlock()
+				continue
+			}
+			// Submit the transaction and mark as funded if successful
+			if err := f.client.SendTransaction(context.Background(), signed); err != nil {
+				websocket.JSON.Send(conn, map[string]string{"error": err.Error()})
+				f.lock.Unlock()
+				continue
+			}
+			f.reqs = append(f.reqs, &request{
+				Username: gist.Owner.Login,
+				Account:  address,
+				Time:     time.Now(),
+				Tx:       signed,
+			})
+			f.history[gist.Owner.Login] = time.Now()
+			fund = true
+		}
+		f.lock.Unlock()
+
+		// Send an error if too frequent funding, othewise a success
+		if !fund {
+			websocket.JSON.Send(conn, map[string]string{"error": fmt.Sprintf("User already funded %s ago", common.PrettyDuration(elapsed))})
+			continue
+		}
+		websocket.JSON.Send(conn, map[string]string{"success": fmt.Sprintf("Funding request accepted for %s into %s", gist.Owner.Login, address.Hex())})
+		select {
+		case f.update <- struct{}{}:
+		default:
+		}
+	}
+}
+
+// loop keeps waiting for interesting events and pushes them out to connected
+// websockets.
+func (f *faucet) loop() {
+	// Wait for chain events and push them to clients
+	heads := make(chan *types.Header, 16)
+	sub, err := f.client.SubscribeNewHead(context.Background(), heads)
+	if err != nil {
+		log.Crit("Failed to subscribe to head events", "err", err)
+	}
+	defer sub.Unsubscribe()
+
+	for {
+		select {
+		case head := <-heads:
+			// New chain head arrived, query the current stats and stream to clients
+			balance, _ := f.client.BalanceAt(context.Background(), f.account.Address, nil)
+			balance = new(big.Int).Div(balance, ether)
+
+			price, _ := f.client.SuggestGasPrice(context.Background())
+			nonce, _ := f.client.NonceAt(context.Background(), f.account.Address, nil)
+
+			f.lock.Lock()
+			f.price, f.nonce = price, nonce
+			for len(f.reqs) > 0 && f.reqs[0].Tx.Nonce() < f.nonce {
+				f.reqs = f.reqs[1:]
+			}
+			f.lock.Unlock()
+
+			f.lock.RLock()
+			for _, conn := range f.conns {
+				if err := websocket.JSON.Send(conn, map[string]interface{}{
+					"funds":    balance,
+					"funded":   f.nonce,
+					"peers":    f.stack.Server().PeerCount(),
+					"requests": f.reqs,
+				}); err != nil {
+					log.Warn("Failed to send stats to client", "err", err)
+					conn.Close()
+					continue
+				}
+				if err := websocket.JSON.Send(conn, head); err != nil {
+					log.Warn("Failed to send header to client", "err", err)
+					conn.Close()
+				}
+			}
+			f.lock.RUnlock()
+
+		case <-f.update:
+			// Pending requests updated, stream to clients
+			f.lock.RLock()
+			for _, conn := range f.conns {
+				if err := websocket.JSON.Send(conn, map[string]interface{}{"requests": f.reqs}); err != nil {
+					log.Warn("Failed to send requests to client", "err", err)
+					conn.Close()
+				}
+			}
+			f.lock.RUnlock()
+		}
+	}
+}