Create you private Ethereum Network
This network would be using Clique (Proof of Authority) consensus protocol.
PreRequirements
1. Create directories
Each node requires a data directory for the blockchain data. When the node starts, Besu saves the node key in this directory.
Create directories for your private network, each of the three nodes, and a data directory for each node:
Clique-Network/
├── Node-1
│ ├── data
├── Node-2
│ ├── data
└── Node-3
├── data
2. Get the address for Node-1
In Clique networks, you must include the address of at least one initial signer in the genesis file. For this Clique network, we’ll use Node-1 as the initial signer. This requires obtaining the address for Node-1.
To get the address for Node-1, in the Node-1
directory, use the public-key export-address
subcommand to write the node address to the specified file (node1Address
in this example).
besu --data-path=data public-key export-address --to=data/node1Address
3. Create the genesis file
The genesis file defines the genesis block of the blockchain (that is, the start of the blockchain). The Clique genesis file includes the address of Node-1 as the initial signer in the extraData
field.
All nodes in a network must use the same genesis file.
Copy the following genesis definition to a file called cliqueGenesis.json
and save it in the Clique-Network
directory:
{
"config":{
"chainId":1981,
"constantinoplefixblock": 0,
"clique":{
"blockperiodseconds":15,
"epochlength":30000
}
},
"coinbase":"0x0000000000000000000000000000000000000000",
"difficulty":"0x1",
"extraData":"0x0000000000000000000000000000000000000000000000000000000000000000<Node 1 Address>0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
"gasLimit":"0xa00000",
"mixHash":"0x0000000000000000000000000000000000000000000000000000000000000000",
"nonce":"0x0",
"timestamp":"0x5c51a607",
"alloc": {
"fe3b557e8fb62b89f4916b721be55ceb828dbd73": {
"privateKey": "8f2a55949038a9610f50fb23b5883af3b4ecb3c3bb792cbcefbd1542c692be63",
"comment": "private key and this comment are ignored. In a real chain, the private key should NOT be stored",
"balance": "0xad78ebc5ac6200000"
},
"627306090abaB3A6e1400e9345bC60c78a8BEf57": {
"privateKey": "c87509a1c067bbde78beb793e6fa76530b6382a4c0241e5e4a9ec0a0f44dc0d3",
"comment": "private key and this comment are ignored. In a real chain, the private key should NOT be stored",
"balance": "90000000000000000000000"
},
"f17f52151EbEF6C7334FAD080c5704D77216b732": {
"privateKey": "ae6ae8e5ccbfb04590405997ee2d52d2b330726137b875053c36d94e974d162f",
"comment": "private key and this comment are ignored. In a real chain, the private key should NOT be stored",
"balance": "90000000000000000000000"
}
},
"number":"0x0",
"gasUsed":"0x0",
"parentHash":"0x0000000000000000000000000000000000000000000000000000000000000000"
}
In extraData
, replace <Node 1 Address>
with the address for Node-1, excluding the 0x prefix.
4. Start the first node as the bootnode
Start Node-1:
besu --data-path=data --genesis-file=../cliqueGenesis.json --network-id 123 --rpc-http-enabled --rpc-http-api=ETH,NET,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="all"
The command line enables:
- The JSON-RPC API using the
--rpc-http-enabled
option - The ETH, NET, and CLIQUE APIs using the
--rpc-http-api
option - All-host access to the HTTP JSON-RPC API using the
--host-allowlist
option - All-domain access to the node through the HTTP JSON-RPC API using the
--rpc-http-cors-origins
option.
When the node starts, the enode URL displays.
5. Start Node-2
Start another terminal, change to the Node-2
directory and start Node-2 specifying the Node-1 enode URL copied when starting Node-1 as the bootnode:
besu --data-path=data --genesis-file=../cliqueGenesis.json --bootnodes=<Node-1 Enode URL> --network-id 123 --p2p-port=30304 --rpc-http-enabled --rpc-http-api=ETH,NET,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="all" --rpc-http-port=8546
The command line specifies:
- A Different port to Node-1 for P2P peer discovery using the
--p2p-port
option. - A Different port to Node-1 for HTTP JSON-RPC using the
--rpc-http-port
option. - The enode URL for Node-1 using the
--bootnodes
option. - The data directory for Node-2 using the
--data-path
option. - Other options as for Node-1.
6. Start Node-3
Start another terminal, change to the Node-3
directory and start Node-3 specifying the Node-1 enode URL copied when starting Node-1 as the bootnode:
besu --data-path=data --genesis-file=../cliqueGenesis.json --bootnodes=<Node-1 Enode URL> --network-id 123 --p2p-port=30305 --rpc-http-enabled --rpc-http-api=ETH,NET,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="all" --rpc-http-port=8547
The command line specifies:
- A different port to Node-1 and Node-2 for P2P peer discovery using the
--p2p-port
option. - A different port to Node-1 and Node-2 for HTTP JSON-RPC using the
--rpc-http-port
option. - The data directory for Node-3 using the
--data-path
option. - The bootnode as for Node-2
- Other options as for Node-1.
7. Confirm the private network is working
Start another terminal, use curl to call the JSON-RPC API net_peerCount
method and confirm the nodes are functioning as peers:
curl -X POST --data '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":1}' localhost:8545
The result confirms Node-1 has two peers (Node-2 and Node-3):
{
"jsonrpc" : "2.0",
"id" : 1,
"result" : "0x2"
}
Stop the nodes
When finished using the private network, stop all nodes using Ctrl+C in each terminal window.