搭建以太坊私链（Win)

安装geth

直接在https://geth.ethereum.org/下载安装即可

配置初始化json

在geth.exe所在目录下，新建genesis.json文件，配置如下:

{
  "config": {
    "chainId": 666,
    "homesteadBlock": 0,
    "eip150Block": 0,
    "eip150Hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "eip155Block": 0,
    "eip158Block": 0,
    "byzantiumBlock": 0,
    "constantinopleBlock": 0,
    "petersburgBlock": 0,
    "istanbulBlock": 0,
    "ethash": {}
  },
  "nonce": "0x0",
  "timestamp": "0x5ddf8f3e",
  "extraData": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "gasLimit": "0x47b760",
  "difficulty": "0x00002",
  "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "coinbase": "0x0000000000000000000000000000000000000000",
  "alloc": {},
  "number": "0x0",
  "gasUsed": "0x0",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000"
}

其中:

• difficulty：表示挖矿难度，参数越小越容易
• gasLimit：转账交易手续费
• nonce: 一个64位随机数，用于挖矿
• extraData: 附加信息，可以填你的个性信息
• coinbase: 矿工账号
• alloc: 用来预置账号以及账号的以太币数量，因为私有链挖矿比较容易，所以我们不需要预置有币的账号，需要的时候自己创建即可以
• timestamp: 设置创世块的时间戳
• parentHash: 上一个区块的hash值，因为是创世块，所以这个值是0
• chainId: 区块链识别ID，不可与主网及其他测试网ID冲突

初始化私链

1. 选择一个目录作为数据存放目录，绝对路径与相对路径皆可，目录不存在则自动创建
2. 执行以下指令: geth —datadir “testchain” init genesis.json

   E:\geth>geth --datadir "testchain" init genesis.json
   INFO [01-22|14:17:37.013] Maximum peer count                       ETH=50 LES=0 total=50
   INFO [01-22|14:17:37.165] Set global gas cap                       cap=25000000
   INFO [01-22|14:17:37.167] Allocated cache and file handles         database=E:\geth\testchain\geth\chaindata cache=16.00MiB handles=16
   INFO [01-22|14:17:37.246] Writing custom genesis block
   INFO [01-22|14:17:37.248] Persisted trie from memory database      nodes=0 size=0.00B time=0s gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
   INFO [01-22|14:17:37.253] Successfully wrote genesis state         database=chaindata                        hash="d3d6bb…c5304a"
   INFO [01-22|14:17:37.257] Allocated cache and file handles         database=E:\geth\testchain\geth\lightchaindata cache=16.00MiB handles=16
   INFO [01-22|14:17:37.363] Writing custom genesis block
   INFO [01-22|14:17:37.364] Persisted trie from memory database      nodes=0 size=0.00B time=0s gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
   INFO [01-22|14:17:37.369] Successfully wrote genesis state         database=lightchaindata                        hash="d3d6bb…c5304a"

   其中:

• —datadir：指定数据文件夹
• init：表示初始化
• genesis.json: 表示创始区块配置文件路径

启动私链

执行以下指令: geth —identity chain —datadir testchain —networkid 666 —nodiscover console 2>log.txt

E:\geth>geth --identity chain --datadir testchain  --networkid 666 --nodiscover console 2>log.txt
Welcome to the Geth JavaScript console!
instance: Geth/chain/v1.9.25-stable-e7872729/windows-amd64/go1.15.6
at block: 0 (Thu Nov 28 2019 17:11:26 GMT+0800 (CST))
 datadir: E:\geth\testchain
 modules: admin:1.0 debug:1.0 eth:1.0 ethash:1.0 miner:1.0 net:1.0 personal:1.0 rpc:1.0 txpool:1.0 web3:1.0
To exit, press ctrl-d
>

其中:

• —identity: 区块链的标示，随便填写，用于标示目前网络的名字
• —datadir：指定数据文件夹
• —networkid 666：指定连接哪个网络，此处666为genesis.json中配置的网络ID
• —nodiscover: 表示不搜索其他节点
• console: 表示启动后打开控制台
• 2>log.txt: 错误记录重定向到log.txt

测试私链

1. 创建账户

   > eth.accounts
   []
   > personal.newAccount("test1")
   "0x193784cea02443b5aeedc3514d3b5f0f01e77eac"
   > personal.newAccount("test2")
   "0xacc1f4deff6900965c02e3a773113dcb8699fcce"
   > eth.accounts
   ["0x193784cea02443b5aeedc3514d3b5f0f01e77eac", "0xacc1f4deff6900965c02e3a773113dcb8699fcce"]
   > eth.getBalance(eth.accounts[0])
   0
   > eth.getBalance(eth.accounts[1])
   0
   >

2. 挖矿测试

   > eth.coinbase
   "0x193784cea02443b5aeedc3514d3b5f0f01e77eac"
   > eth.getBalance(eth.accounts[0])
   0
   > eth.getBalance(eth.accounts[1])
   0
   > eth.accounts
   ["0x193784cea02443b5aeedc3514d3b5f0f01e77eac", "0xacc1f4deff6900965c02e3a773113dcb8699fcce"]
   > miner.start()
   null
   > eth.mining
   true
   > miner.stop()
   null
   > eth.getBalance(eth.accounts[0])
   20000000000000000000
   >