Ethereum Dev Chain - Private Chain

To develop and test an Ethereum smart contract we need a test network. The easiest way is go get spin off our own test chain with sufficient amount ethers. Below are the steps for spinning a development chain.

First download the latest Geth from the below URL

https://geth.ethereum.org/downloads/

As I am using a windows machine, I downloaded the windows version. Install the Geth on your machine as per the installation guide.

Create a folder called DevChain where you can keep the chain data.

After that let’s create an account using command prompt. Specify the password when prompted.

Now create a genesis file to define the genesis block, which is the start of the block chain. Here is the genesis file (“genesis_dev.json”) I am using. Replace the account number with number you got in the previous step.

{

  "nonce": "0x0000000000000042",

  "difficulty": "0x200",

  "config": {

    "chainId": 15,

    "homesteadBlock": 0,

    "eip155Block": 0,

    "eip158Block": 0

  },

  "alloc": {

    "0x0bd615694d433424c292599f080bda45b0c257fc": {

      "balance": "100000000000000000000000"

    }

  },

  "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",

  "coinbase": "0x0000000000000000000000000000000000000000",

  "timestamp": "0x00",

  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",

  "gasLimit": "0x8000000"

}

Now create a batch file (“startgeth.bat”) which will initialize the network every time you run.

RD /S /Q %~dp0\devChain\geth

geth.exe --datadir=devChain init genesis_dev.json

geth.exe --mine --networkid=12345 --cache=2048 --maxpeers=0 --datadir=devChain --rpc --rpccorsdomain "*" --rpcapi "eth,web3,personal,net,miner,admin,debug" console 

Now run the batch file to initialize and start the test network.

Now our development network is ready to start deploying and testing smart contracts.