How to Install Private Ethereum Blockchain 3 nodes in 5 steps

Install private Ethereum blockchain with 3 nodes tutorial, Biastek will show you 3 ways to setup private Ethereum. It depends on the using purpose, we should have suitable installation

Install Private Ethereum Blockchain without docker
Install Private Ethereum Blockchain with docker
Install Private Ethereum Blokchain with OpenZeppelin

In this tutorial, we have 5 steps:

Install prerequisites
Set up Ethereum
Run Ethereum
Add Peers
Testing Ethereum

Now let’s start from step 1

1. Set up prerequisites

Install Ubuntu 18.04 and install essential package

$ sudo apt-get update

$ sudo apt-get install build-essential

$ sudo apt-get upgrade

2. Set up Ethereum

Setup Geth

$ sudo add-apt-repository -y ppa:ethereum/ethereum

$ sudo apt-get update

$ sudo apt-get install ethereum

Create new accounts

Create new account in 3 Peers with the below comand line

$ geth –datadir=./chaindata/ account new

After create Account, it is will generate a folder “chaindata” which store data of Ethereum Blockchain. Besides, should save account and private key and put it to genesis.json file in next step.
For example account in Peer 0

Public address of the key: 0xa352f2B91073472DF757248F9F06d8716d8b5123 Path of the secret key file: chaindata/keystore/UTC–2020-05-10T04-34-53.009776823Z–a352f2b91073472df757248f9f06d8716d8b5123

Create Genesis.json file

The Genesis File is the config file for creating/initializing a blockchain. Every (yes , every) new client joining an ethereum network must get a copy of the genesis file in order to properly initialize itself. Two clients with different genesis file will be able to “connect” to each other but not to work on the same blockchain

$vi genesis.json

{
“coinbase” : “0x0000000000000000000000000000000000000001”,
“difficulty” : “0x1”,
“extraData” : “”,
“gasLimit” : “0x47b760”,
“nonce” : “0x0000000000000042”,
“mixhash” : “0x0000000000000000000000000000000000000000000000000000000000000000”,
“parentHash” : “0x0000000000000000000000000000000000000000000000000000000000000000”,
“timestamp” : “0x00”,
“alloc”: {
“6cdbBD2e4DcbC0020b5D0Bb9B3500A001c14B078”: { “balance”: “0x1337000000000000000000” },// Account of Peer 0
“BdB8a18307931D887AA1F5609E6daD54c6004530”: { “balance”: “0x1337000000000000000000” }, //Account of Peer 1
“93AB0c01550DD1d505301dCD4B87932244608399”: { “balance”: “0x1337000000000000000000” }, //Account of Peer 2
//These accounts for re-funding
“4f1809cf76a8946d615cb546271cae3ea36328ed”: {
“balance”: “0x200000000000000000000000000000000000000000000000000000000000000”
},
“7d4684e8f1827832f13124b13874b00890a8a83f”: {
“balance”: “0x200000000000000000000000000000000000000000000000000000000000000”
},
“6206d535d4af9bd3327167027dbb2fffa070fc68”: {
“balance”: “0x200000000000000000000000000000000000000000000000000000000000000”
},
“362bfe247396ecc09d30091e3c5ca2d5f527bd06”: {
“balance”: “0x200000000000000000000000000000000000000000000000000000000000000”
},
“ca1c753ed477ac905f4ec6c9851bc81f0fb41512”: {
“balance”: “0x200000000000000000000000000000000000000000000000000000000000000”
},
“61cfb9bc71d6f2747598db3f767b4b8967f029ab”: {
“balance”: “0x200000000000000000000000000000000000000000000000000000000000000”
}
},
“config”: {
“chainId”: 22,
“homesteadBlock”: 0,
“eip155Block”: 0,
“eip158Block”: 0,
“eip150Block”: 0,
“byzantiumBlock”: 0,
“constantinopleBlock”: 0,
“petersburgBlock”: 0
}
}

Start Ethereum

$geth –datadir=./chaindata/ init ./genesis.json

After start with above comand line, it will create geth.ipc file

3.Run Ethereum

Start Ethereum with mining process

$geth –identity “process-node” –datadir=./chaindata/ –mine –minerthreads=1 –allow-insecure-unlock –rpc –networkid 22 –rpcaddr “127.0.0.1” –rpcport 8545 –rpcapi=”db,eth,net,web3,personal” –rpccorsdomain “*”

$geth –identity “process-node” –datadir=./chaindata/ –mine –minerthreads=1 –allow-insecure-unlock –rpc –cache=1024 –syncmode “fast” –networkid 22 –rpcaddr “127.0.0.1” –rpcport 8545 –rpcapi=”db,eth,net,web3,personal” –rpccorsdomain “*”

Start Ethereum without mining process, remove –mine –miner threads=1

$geth –identity “process-node” –datadir=./chaindata/ –allow-insecure-unlock –rpc –networkid 22 –rpcaddr “127.0.0.1” –rpcport 8545 –rpcapi=”db,eth,net,web3,personal” –rpccorsdomain “*”

By default, account is locked after create, in order to unlock account using “allow-insecure-unlock” in command start Ethereum
After run mining command line ethereum wil generate geth.ipc file.
Unlock account

When deploy smart contract, account have to be unlock. Unlock account with below command line

$ personal.unlockAccount(eth.accounts[0])

4.Add Peers

Attach to blockchain with command

$ geth attach ~/chaindata/geth.ipc

Using command “admin.nodeInfo” to show enode

Add Peers use this command line with node info

admin.addPeer(“enode://da0111d59240f1d9930360625d274f0a655da64c9f16276eda63bb94e4e10d09f154c940308a71685248e29639027e70b9b965487f38f4cf032e7d27db22d99d@192.168.70.135:30303”)