入门安装go-etherenum
1 搭建私有链
1.1 安装
官方文档提供两种方式，本文使用源码编译
下载源码
git clone https://github.com/ethereum/go-ethereum
安装golang
yum install golang
编译
cd go-ethereum make geth
1.2 config配置文件
{
"coinbase" : "0x0000000000000000000000000000000000000000",
"difficulty" : "0x400",
"extraData" : "0x0",
"gasLimit" : "0x2fefd8",
"nonce" : "0xdeadbeefdeadbeef",
"mixhash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
"parentHash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
"timestamp" : "0x00",
"alloc" : {}
}异常
go-ethereum/build/bin/geth init go-ethereum/eth/piccgenesis.json Fatal: invalid genesis file: json: cannot unmarshal hex string without 0x prefix into Go struct field Genesis.extraData of type hexutil.Bytes
执行成功的config.json
[root@iz2ze20vl8jnph0si0n7jsz watt]# go-ethereum/build/bin/geth init go-ethereum/eth/piccgenesis.json INFO [01-29|21:20:19] Allocated cache and file handles database=/root/.ethereum/geth/chaindata cache=16 handles=16 Fatal: Failed to write genesis block: database already contains an incompatible genesis block (have d4e56740f876aef8, new a0e580c6769ac3dd)
原因由于上次执行命令初始化
启动私有链节点
启动Geth即可以启动以太坊的区块链，为了构建私有链 ，需要在Geth启动时加入一些参数，Geth参数含义如下：
build/bin/geth --datadir /home/watt/ethereumdata init eth/piccgenesis.json
config.json文件
{
"config": {
"chainId": 15,
"homesteadBlock": 0,
"eip155Block": 0,
"eip158Block": 0
},
"coinbase" : "0x0000000000000000000000000000000000000000",
"difficulty" : "0x40000",
"extraData" : "",
"gasLimit" : "0xffffffff",
"nonce" : "0x0000000000000042",
"mixhash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
"parentHash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
"timestamp" : "0x00",
"alloc": { }
}有个疑问那初始化的数据存储路径在哪呢？ 通过指定的路径生成数据文件名称，使用find命令查找如下
查看初始化数据文件大小如下
重新配置参数
获取当前的目录 /home/watt/go-ethereum/build/bin/geth --datadir "/home/watt/ethereumchain" init /home/watt/go-ethereum/eth/piccgenesis.json 创建数据存放地址并初始化创世块 /home/watt/go-ethereum/build/bin/geth --identity "PICCetherum" --rpc --rpccorsdomain "*" --datadir "/home/watt/ethereumchain" --port "30303" --rpcapi "db,eth,net,web3"--networkid 95518 console
启动日志
INFO [01-29|22:08:58] Allocated cache and file handles database=/home/watt/ethereumchain/geth/chaindata cache=16 handles=16
INFO [01-29|22:08:58] Writing custom genesis block
INFO [01-29|22:08:58] Successfully wrote genesis state database=chaindata hash=a0e580…a5e82e
INFO [01-29|22:08:58] Allocated cache and file handles database=/home/watt/ethereumchain/geth/lightchaindata cache=16 handles=16
INFO [01-29|22:08:58] Writing custom genesis block
INFO [01-29|22:08:58] Successfully wrote genesis state database=lightchaindata hash=a0e580…a5e82e
[root@iz2ze20vl8jnph0si0n7jsz go-ethereum]# /home/watt/go-ethereum/build/bin/geth --identity "PICCetherum" --rpc --rpccorsdomain "*" --datadir "/home/watt/ethereumchain" --port "30303" --rpcapi "db,eth,net,web3"--networkid 95518 console
INFO [01-29|22:09:20] Starting peer-to-peer node instance=Geth/PICCetherum/v1.8.0-unstable-722bac84/linux-amd64/go1.8.3
INFO [01-29|22:09:20] Allocated cache and file handles database=/home/watt/ethereumchain/geth/chaindata cache=128 handles=1024
WARN [01-29|22:09:20] Upgrading database to use lookup entries
INFO [01-29|22:09:20] Initialised chain configuration config="{ChainID: 15 Homestead: 0 DAO: <nil> DAOSupport: false EIP150: <nil> EIP155: 0 EIP158: 0 Byzantium: <nil> Engine: unknown}"
INFO [01-29|22:09:20] Disk storage enabled for ethash caches dir=/home/watt/ethereumchain/geth/ethash count=3
INFO [01-29|22:09:20] Disk storage enabled for ethash DAGs dir=/root/.ethash count=2
INFO [01-29|22:09:20] Initialising Ethereum protocol versions="[63 62]" network=1
INFO [01-29|22:09:20] Database deduplication successful deduped=0
INFO [01-29|22:09:20] Loaded most recent local header number=0 hash=a0e580…a5e82e td=262144
INFO [01-29|22:09:20] Loaded most recent local full block number=0 hash=a0e580…a5e82e td=262144
INFO [01-29|22:09:20] Loaded most recent local fast block number=0 hash=a0e580…a5e82e td=262144
INFO [01-29|22:09:20] Regenerated local transaction journal transactions=0 accounts=0
INFO [01-29|22:09:20] Starting P2P networking
INFO [01-29|22:09:22] UDP listener up self=enode://4fadb2bd1b9e7efca20c99c067930c7bb5cd9c27ea38aef11fd514bed4abb1b2697651194fd1b765a51c3648e001542fbf57ef2c4912469e384139bb61c57f60@[::]:30303
INFO [01-29|22:09:22] HTTP endpoint opened: http://127.0.0.1:8545
INFO [01-29|22:09:22] IPC endpoint opened: /home/watt/ethereumchain/geth.ipc
INFO [01-29|22:09:22] RLPx listener up self=enode://4fadb2bd1b9e7efca20c99c067930c7bb5cd9c27ea38aef11fd514bed4abb1b2697651194fd1b765a51c3648e001542fbf57ef2c4912469e384139bb61c57f60@[::]:30303卡住了，需要把root下的
rm -rf ethereumchain/ rm -rf .ethereum/
清除后重现执行执行输出如下：
INFO [01-29|22:47:57] HTTP endpoint opened: http://127.0.0.1:8545 INFO [01-29|22:47:57] RLPx listener up self=enode://fc07f632a636c713a2621902d5eac3b1969afd54d255812ac767484d926fd1d5113d243467e59e8c0864e63b60240dbd7d55d3b34058fa388f1002f6b20bcfec@[::]:30303 INFO [01-29|22:47:57] IPC endpoint opened: /home/watt/ethereumchain/geth.ipc INFO [01-29|22:48:17] Block synchronisation started INFO [01-29|22:48:24] Imported new block headers count=192 elapsed=1.250s number=192 hash=723899…123390 ignored=0 INFO [01-29|22:48:24] Imported new block headers count=384 elapsed=53.824ms number=576 hash=41a746…6a8b38 ignored=0 INFO [01-29|22:48:24] Imported new block receipts count=2 elapsed=17.637ms bytes=8 number=2 hash=b495a1…4698c9 ignored=0 INFO [01-29|22:48:24] Imported new block headers count=384 elapsed=55.720ms number=960 hash=916910…1d0e2a ignored=0 INFO [01-29|22:48:24] Imported new block receipts
但是未能调用javasript console页面 通过查询发现需要增加 --dev 参数 另开窗口
输入命令
/home/watt/go-ethereum/build/bin/geth --dev console 2>> file_to_log_output
2
2、 使用私有链
查看账户
eth.accounts
创建用户：
personal.newAccount("111111")其中参数为此账户的密码。
也可以先创建账户，然后输入密码：
personal.newAccount()
查看区块数据
eth.blockNumber
启动挖矿
miner.start()
返回结果为true则启动成功，具体执行情况可查看日志。
停止挖矿
miner.stop()
当在执行挖矿时日志会不停刷屏，不用管，只要命令输入全，执行即可停止挖矿。
查看账户余额
其中参数为区块链地址
eth.getBalance("0x7d1f7be4112ce63b9de04a0bf95c1e87e430bd1b")转账
从账户0x7d1f7be4112ce63b9de04a0bf95c1e87e430bd1b转账3个以太币到0x587e57a516730381958f86703b1f8e970ff445d9。
eth.sendTransaction({from:"0x7d1f7be4112ce63b9de04a0bf95c1e87e430bd1b",to:"0x587e57a516730381958f86703b1f8e970ff445d9",value:web3.toWei(3,"ether")})当直接执行此方法时会抛出异常：
account is locked
at web3.js:3119:20
at web3.js:6023:15
at web3.js:4995:36
at <anonymous>:1:1很明显，账户被锁。
解锁转出账户
其中第一个参数为转出账户，第二个参数为密码。也可以直填写第一个参数，然后通过命令行提示再输入密码。
personal.unlockAccount("0x7d1f7be4112ce63b9de04a0bf95c1e87e430bd1b","111111")解锁完成之后，即可执行转账操作。但此时查看时会发现接收账户依旧为原来数值。此时需要执行挖矿命令，才会把转账真正完成。
看似美好，执行命令后
> eth.accounts
["0x709447961e479f696a496243cbeff83b851908b2"]
> personal.newAccount("111111")
"0x489835dff4d2270ae2c6a148ca313858bf1e4994"
> eth.blockNumber
0
> miner.start()
null
>
发现miner.start() 为null
Pre-allocating ether to your account
A difficulty of “0x400” allows you to mine Ether very quickly on your private testnet chain. If you create your chain and start mining, you should have hundreds of ether in a matter of minutes which is way more than enough to test transactions on your network. If you would still like to pre-allocate Ether to your account, you will need to:
Create a new Ethereum account after you create your private chain
Copy your new account address
Add the following command to your Custom_Genesis.json file:
"alloc":
{
"0x709447961e479f696a496243cbeff83b851908b2":
{ "balance": "20000000000000000000" }
}
Note
Replace 0x1fb891f92eb557f4d688463d0d7c560552263b5a with your account address.
Save your genesis file and rerun your private chain command. Once geth is fully loaded, close it by .
We want to assign an address to the variable primary and check its balance.
Run the command geth account list in your terminal to see what account # your new address was assigned.需要执行命令
miner.setEtherbase(personal.listAccounts[0])
查看日志
INFO [01-29|23:14:53] Starting mining operation INFO [01-29|23:14:53] Commit new mining work number=1 txs=0 uncles=0 elapsed=65.571µs WARN [01-29|23:14:53] Block sealing failed err="waiting for transactions
继续努力
#返回钱包管理的账户地址列表
#返回示例：["0x3138e3722fb4280cb67f6e858108136bfa1c9160"]
eth.accounts
#创建账户地址，参数为账户锁定密码，在转账前需要先解锁账户
#我们把这个命令运行两次，创建两个地址，加上默认的，一共有了三个账户地址
personal.newAccount('111111')
personal.newAccount('111111')
#为账户设置别名，方便命令输入
user1=eth.accounts[0]
user2=eth.accounts[1]
user3=eth.accounts[2]
#查看地址user1余额,这个地址是测试链默认开通的一个地址，里面初始化有很多币
#我们创建的另外两个地址余额未0
eth.getBalance(user1)
#查看区块高度，现在为0
eth.blockNumber
#转账测试，首先解锁账号user1
#命令运行后要求输入解锁密码，直接回车，默认账号锁定密码为空，返回true成功
personal.unlockAccount(user1)
#从user1向user2转账3个以太币
#命令运行后，提交交易立马回出发挖矿
eth.sendTransaction({from:user1,to:user2,value:web3.toWei(3,"ether")})
#查看区块高度，这时高度为1
eth.blockNumber还是null
挖矿测试
geth启动后，自动启动挖矿，这时运行miner.start()，返回为null 无交易的时候不挖矿，当有交易时自动会触发挖矿流程
#我们可以先停止挖矿
miner.stop()
#提交交易，这时候只提交，查看账户余额，但是未确认
eth.sendTransaction({from:user1,to:user2,value:web3.toWei(3,"ether")})
#启动挖矿，确认交易，再次查看账户余额
miner.start()
#那么挖矿奖励去哪儿了？查看矿工地址
eth.coinbase
#设置矿工地址
miner.setEtherbase(eth.coinbase)3、参考资料
区块链开发（一）搭建基于以太坊的私有链环境
私有链搭建文档
以太坊学习笔记：私有链搭建操作指南
区块链开发（二）以太坊客户端基本操作命令
以太坊执行miner.start返回null
10分钟完成阿里云环境搭建以太坊私有链
