ethereum-private-network

Instructions on how to setup an ethereum private test network for development. This was done with Mac OS X.

Pre-requisities

• homebrew

Install Geth

Geth is the command line interface for running a full ethereum node implemented in Go.

brew update

brew upgrade

brew tap ethereum/ethereum

brew install ethereum

Initialize local test network

The first thing you need to do is initialize your ethereum test network:

bin/init

This script will clear/reset your ethereum blockchain and create the following accounts:

[{
  address: '0x5DFE021F45f00Ae83B0aA963bE44A1310a782fCC',
  ether: 200000,
  privateKey: '0xf059416a2f6bb05d0770bbacb24a6430757aa7db5c15959838ed142b486df5b8',
  hasWallet: true,
  password: 'iloveethereum',
  coinbase: true
},
{
  address: '0xFE2b768a23948EDDD7D7Caea55bAa31E39045382',
  ether: 10,
  privateKey: '0xb32e083f4ce24956c2989d7e0c57bfd6759b3fa7ba8730c342e12fdf4ba8deb6',
  hasWallet: true,
  password: 'iloveethereum'
},
{
  address: '0xA9a418dA22532Bd1189fF8Be5Cdaf3570bF9da43',
  ether: 20,
  privateKey: '0x5fb75cc4852a0340e6bb061d039974809d36e6974ff849d3b3586909b65829d8',
  hasWallet: true,
  password: 'iloveethereum'
},{
  address: '0x9F3A4BBeD4660F2DCCd6E980e2FaA6d6214E5Dc8',
  ether: 30,
  privateKey: '0x6ac723a720aa0efa5939a8526ec98dbc1bc6f81146b24fdf9f3e1d09a993c222',
  hasWallet: true,
  password: 'iloveethereum'
},{
  address: '0xc10261166b4699D3c1535Aa30AC29446c755f065',
  ether: 40,
  privateKey: '0x9160633fbdb0bf99f444a3c6018d8a6e4a9a353f0745bb56e43025648118dc27',
  hasWallet: true,
  password: 'iloveethereum'
},{
  address: '0xe480219e1904de4500Cd8459C74d388457A3f3Ec',
  ether: 0,
  privateKey: '0xba774bc82c19dee108f3da59f33aabcec8155f6d102adce371186fec839d50ef',
  hasWallet: true,
  password: 'iloveethereum'
},
},{
  address: '0xED7211F84b37B0f62d345462fFeB56b57B787539',
  ether: 0,
  privateKey: '0xb34f18662b6d09bc01b2b26e3d325b03f824cb10be8226ad65b1f4cac457eb73',
  hasWallet: true,
  password: 'iloveethereum'

},{
  address: '0xCC52165260FB50dA8Fc9fEd714e33884D324f7Dd',
  ether: 70,
  privateKey: '0x1de8d3b032083b477f623d4fc004a120459ed17688aa5311c7fbcf30a21ec0e4',
  hasWallet: false
}
},{
  address: '0x28c36458566E89b3F9F3D5c1Ba52FDF840072598',
  ether: 0,
  privateKey: '0x26fd4b1dbbea7c356b4ae3b32d617fa7df301f3ed26873dcc90cd86862867bcd',
  hasWallet: false
}

Start ethereum mining node

The ethereum network needs a mining node to process transactions:

bin/mine

The first time you run geth on your machine, it will generate a DAG. This can take several minutes depending upon the speed of your CPU. Once it finishes generating the DAG, it will start mining and generating messages like this:

I0124 14:41:07.325501 miner/unconfirmed.go:83] 🔨  mined potential block #1 [f60eb249…], waiting for 5 blocks to confirm
I0124 14:41:07.325835 miner/worker.go:516] commit new work on block 2 with 0 txs & 0 uncles. Took 225.475µs

The mining node deposits ethereum into the following account:

0x5DFE021F45f00Ae83B0aA963bE44A1310a782fCC

Attach to your mining node

You can interact with the ethereum network by attaching to your mining node:

bin/attach

This will present a javascript console where you can run various commands

Send ether from one account to another

Form the console attached to your mining node, you can send ether from one account to another. First we check the balances of the from and to accounts:

var from = web3.eth.accounts[1]

personal.unlockAccount(from, 'iloveethereum')

web3.eth.getBalance(from)

10000000000000000000

var to = web3.eth.accounts[2]

web3.eth.getBalance(to)

20000000000000000000

Now we send ether:

eth.sendTransaction({from: from, to: to, value: 1})

"0xdc6a6858f57c100398dabb5868549a6a113508b40bcc43b5b5aad639821c3fad"

If you check the mining node console, you will see this transaction logged:

I0124 09:35:24.849818 internal/ethapi/api.go:1047]
Tx(0xdc6a6858f57c100398dabb5868549a6a113508b40bcc43b5b5aad639821c3fad)
to: 0x22fb800aaeab6af13e8fd76623b6acab3ee15b62

Now you can check the balances of the from and to account to verify that ether was moved:

web3.eth.getBalance(from)

9999579999999999999

NOTE: The reason more than 1 is gone from the ether balance is because it costs ether to execute the send ether transaction. This transaction fee is given to the miner.

web3.eth.getBalance(to)

20000000000000000001

Deploy the greeter contract and call the greet method

From the attached console, you can deploy the greeter smart contract and use it:

loadScript('deploy.js');

Contract mined! address: 0x1b9dfd2ea79f59491b7881c508010af5410cd096 transactionHash: 0xe92dfdbea562e59661a483f21b8d2fedebebe4eb0b9cee00bfc9fb97ffa329e6
null [object Object]
Contract mined! address: 0xe9f5d76475b180a709025dde31091b9793742119 transactionHash: 0x1ca2b4240d5957ea68ff9dc5aeee08050b8d533e1636586e47ad9222b945b1f1

greeter.greet();

"hello private test network"

NOTE: The contract in deploy.js is the default contract displayed in the online solidity compiler