Create a private chain with geth

Install:

Official website address

Remove node:

geth removedb --datadir node1
geth removedb --datadir node2
geth removedb --datadir node3

Create genesis.json:

{
  "config": {
    "chainId": 6666,
    "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": "0xffffffff",
  "difficulty": "0x0200",
  "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "coinbase": "0x0000000000000000000000000000000000000000",
  "alloc": { },
  "number": "0x0",
  "gasUsed": "0x0",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000"
}

Genesis configuration parameter description:

• nonce: 64-bit random number, used for mining
• timestamp: the timestamp of the genesis block
• parentHash: The value of the previous block hash, because it is a genesis block, so this value is 0
• mixHash: nonceused for mining in conjunction with, generated by part of the previous blockhash
• extraData: Additional information, fill in arbitrarily
• gasLimit: GASThe total consumption limit of the pair, which is used to limit the sum of the transaction information that the block can contain
• difficulty: difficulty value, the bigger the more difficult
• coinbase: the miner's account. After the first block is mined, the miner's account will be rewarded with ether.
• alloc: The default account and the amount of ether in the account, the test chain is easier to mine and can not be configured
• chainId: An independent blockchain network ID is specified, and nodes of different ID networks cannot be connected to each other

Initialize the node:

geth --datadir node1 init genesis.json
geth --datadir node2 init genesis.json

If an error is reported when initializing the genesis block:

Failed to write genesis block: unsupported fork ordering: eip150Block not enabled, but eip155Block enabled at 0

The original genesis block needs to be removed first

geth removedb --datadir node1

Reinitialize the genesis block

Start the node:

geth --datadir "node1" --networkid 6666 --port 10010 --http --http.api "eth,net,web3,miner,admin" --http.addr "localhost" --http.port 8546 console 2>node1.log
geth --datadir "node2" --networkid 6666 --port 10011 --http --http.api "eth,net,web3,miner,admin" --http.addr "localhost" --http.port 8547 console 2>node2.log

View the information of your own node:

admin.nodeInfo

Add node:

admin.addPeer('enode://535bb7b99b8dacd1011484ff3007c77809946b5869e8ab2e30c616bf8eb012d60eecc71e58ebcfbb7c0265b82a4f342e6a107a6b51f6f0ed2d1084c57aba55ae@[::]:10011')

View the node list:

admin.peers

Check account:

Read the account address information in the local keystore directory

eth.accounts
#或
personal.listAccounts

create Account:

The input parameter is the password, and the account address is stored in the keystore directory.

personal.newAccount()
#或
personal.newAccount(password)

Import account by private key:

The first parameter is the private key with 0x removed, and the second parameter is the password

personal.importRawKey("a290e50c1cde5128229cf9e286593c443084646e65e97c1bcd8afdaddea78fa7","111")

Unlock account:

personal.unlockAccount(account)

An error is reported when personal.unlockAccount() is executed: 

geth新版本error：account unlock with HTTP access is forbidden at web3.js……

Reason for exception: In the new version of geth, for security reasons, the HTTP channel unlocking account is disabled by default

Solution: start node command add --allow-insecure-unlock

Check balances:

The balance is displayed in the smallest unit by default: 1 ETH=10 to the 18th power of wei

eth.getBalance(account1)
# ETH
web3.fromWei(eth.getBalance(account),'ether')

Current block:

eth.blockNumber

Start digging:

miner.start()
# x是启动几个核心
miner.start(x)
# 成功挖到一次后就停止
miner.start(1);admin.sleepBlocks(1);miner.stop()

End digging:

miner.stop()

Set up a mining account:

miner.setEtherbase(account)

transfer:

Before transferring money, you need to execute personal.unlockAccount() to unlock the account

The transfer will be successful only after miner.start() is executed

eth.sendTransaction({from:account1,to:account2,value:web3.toWei(5,'ether')})

Connect to the geth network using Metamask