ethercheats

Cheatsheet for Private Ethereum Chains

Installation

Install geth from https://geth.ethereum.org/downloads/. In Windows: Add installation path to environment variable PATH.

Create a folder for your Blockchain: blockChainFolder

Blockchain Creation

Create a genesis.json in your blockChainFolder. Use a random chainId, keep difficulty low to mine fast.

{
    "config": {
        "chainId": 2017,
        "homesteadBlock": 0,
        "eip155Block": 0,
        "eip158Block": 0
    },
    "difficulty": "0x10000",
    "gasLimit": "2100000",
    "alloc": {}
}

Blockchain Setup

You can either create a private chain or connect to a network:

Private Chain

Create a private blockchain in your blockChainFolder with your shell:

geth --datadir="ethdata" init genesis.json

Create a network for the private blockchain and start a console, chose a random (high) networkid:

geth --datadir="ethdata" --networkid 20123 console

Now you have access to your blockchain via console.

Connect to Network

Connect to a network:

geth --datadir="ethdata" --networkid [aNetworkId] --rpcport [aPort] --rpcaddr [aIp] --rpc console --ipcdisable

networkid - the networkid of your chain e.g. 20123

rpcport - a unique port e.g. 8001

rpcaddr - your address in the network e.g. 10.0.0.2

Get your enode

admin.nodeInfo.enode

This looks like

enode://616f524fecc375df460c7d47fc84d9b2049a1feac0d15c956a7b93ae84916e2fbd928b2d544d16c5f9be8d5516992019438bcdebaba7177248c624fc2bd34aac@[::]:30303

Replace [::] with your ip and give it to your partner.

Your partner adds you with:

admin.addPeer('enode://616f524fecc375df460c7d47fc84d9b2049a1feac0d15c956a7b93ae84916e2fbd928b2d544d16c5f9be8d5516992019438bcdebaba7177248c624fc2bd34aac@10.0.0.2:30303')

See all participants with

admin.peers

Accounts and Balances

Create an account:

personal.newAccount('insertYourPasswordHere')

You receive an address like 0x29fbf84ff0f76d0b720d1b22de0aabd8779e362d.

Show all accounts:

eth.accounts

Assuming yours is the first in the list, you get your Balance with:

eth.getBalance(eth.accounts[0])

You can also pass your address directly to the getBalance function.

eth.getBalance('0x29fbf84ff0f76d0b720d1b22de0aabd8779e362d')

Mining

To get ether, we need to mine some blocks.

Bind the miner to your address:

miner.setEtherbase(eth.accounts[0])

To start mining:

miner.start()

Wait some time, then stop the miner with:

miner.stop()

Let's take a look how rich you are:

eth.getBalance(eth.accounts[0])

Transactions

Now create another account like explained above.

Unlock your account:

personal.unlockAccount(eth.accounts[0], 'insertYourPasswordHere')

It's time to spend your money:

eth.sendTransaction({from: eth.accounts[0], to: eth.accounts[1], value: 202020})

The money is not directly available in the second account, the transaction has to be mined first. So start and stop the miner as explained above and check out the balances.