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

cmd/puppeth/wizard_genesis.go

@@ -0,0 +1,136 @@
+// 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/>.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"math/big"
+	"math/rand"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+// makeGenesis creates a new genesis struct based on some user input.
+func (w *wizard) makeGenesis() {
+	// Construct a default genesis block
+	genesis := &core.Genesis{
+		Timestamp:  uint64(time.Now().Unix()),
+		GasLimit:   4700000,
+		Difficulty: big.NewInt(1048576),
+		Alloc:      make(core.GenesisAlloc),
+		Config: &params.ChainConfig{
+			HomesteadBlock: big.NewInt(1),
+			EIP150Block:    big.NewInt(2),
+			EIP155Block:    big.NewInt(3),
+			EIP158Block:    big.NewInt(3),
+		},
+	}
+	// Figure out which consensus engine to choose
+	fmt.Println()
+	fmt.Println("Which consensus engine to use? (default = clique)")
+	fmt.Println(" 1. Ethash - proof-of-work")
+	fmt.Println(" 2. Clique - proof-of-authority")
+
+	choice := w.read()
+	switch {
+	case choice == "1":
+		// In case of ethash, we're pretty much done
+		genesis.Config.Ethash = new(params.EthashConfig)
+		genesis.ExtraData = make([]byte, 32)
+
+	case choice == "" || choice == "2":
+		// In the case of clique, configure the consensus parameters
+		genesis.Difficulty = big.NewInt(1)
+		genesis.Config.Clique = &params.CliqueConfig{
+			Period: 15,
+			Epoch:  30000,
+		}
+		fmt.Println()
+		fmt.Println("How many seconds should blocks take? (default = 15)")
+		genesis.Config.Clique.Period = uint64(w.readDefaultInt(15))
+
+		// We also need the initial list of signers
+		fmt.Println()
+		fmt.Println("Which accounts are allowed to seal? (mandatory at least one)")
+
+		var signers []common.Address
+		for {
+			if address := w.readAddress(); address != nil {
+				signers = append(signers, *address)
+				continue
+			}
+			if len(signers) > 0 {
+				break
+			}
+		}
+		// Sort the signers and embed into the extra-data section
+		for i := 0; i < len(signers); i++ {
+			for j := i + 1; j < len(signers); j++ {
+				if bytes.Compare(signers[i][:], signers[j][:]) > 0 {
+					signers[i], signers[j] = signers[j], signers[i]
+				}
+			}
+		}
+		genesis.ExtraData = make([]byte, 32+len(signers)*common.AddressLength+65)
+		for i, signer := range signers {
+			copy(genesis.ExtraData[32+i*common.AddressLength:], signer[:])
+		}
+
+	default:
+		log.Crit("Invalid consensus engine choice", "choice", choice)
+	}
+	// Consensus all set, just ask for initial funds and go
+	fmt.Println()
+	fmt.Println("Which accounts should be pre-funded? (advisable at least one)")
+	for {
+		// Read the address of the account to fund
+		if address := w.readAddress(); address != nil {
+			genesis.Alloc[*address] = core.GenesisAccount{
+				Balance: new(big.Int).Lsh(big.NewInt(1), 256-7), // 2^256 / 128 (allow many pre-funds without balance overflows)
+			}
+			continue
+		}
+		break
+	}
+	// Add a batch of precompile balances to avoid them getting deleted
+	for i := int64(0); i < 256; i++ {
+		genesis.Alloc[common.BigToAddress(big.NewInt(i))] = core.GenesisAccount{Balance: big.NewInt(1)}
+	}
+	fmt.Println()
+
+	// Query the user for some custom extras
+	fmt.Println()
+	fmt.Println("Specify your chain/network ID if you want an explicit one (default = random)")
+	genesis.Config.ChainId = big.NewInt(int64(w.readDefaultInt(rand.Intn(65536))))
+
+	fmt.Println()
+	fmt.Println("Anything fun to embed into the genesis block? (max 32 bytes)")
+
+	extra := w.read()
+	if len(extra) > 32 {
+		extra = extra[:32]
+	}
+	genesis.ExtraData = append([]byte(extra), genesis.ExtraData[len(extra):]...)
+
+	// All done, store the genesis and flush to disk
+	w.conf.genesis = genesis
+}