Geth --chain option?

Question

I am trying to connect geth to a private blockchain running parity nodes and I don't know how. Some of my research leads me to this page: how to connect "Kovan" or "Rinkeby" from geth

They mention the "--chain" option. But I don't see that option here: https://github.com/ethereum/go-ethereum/wiki/Command-Line-Options

Can anyone tell me what --chain is? Can anyone tell me if that is the same as the genesis file?

Thank you.

Answer 1

There is no --chain option for geth. You can build geth and start it at private blockchain, as follows:

1. Install go

2. Clone go-ethereum project by git clone https://github.com/ethereum/go-ethereum.git

3. Rebuild all commands by make all. For example geth
4. Test whether everything is ok. ./build/bin/geth --datadir=./dev/data0 --networkid 2 console. At first you should create directory ./dev/data0 to save chain data. If Ok, now you have entered geth console on private blockchain.

If you want to use genesis.json custom some properties, as follows:

1: create a simple genesis.json file

{
    "config": {
        "chainId": 10,
        "homesteadBlock": 0,
        "eip155Block": 0,
        "eip158Block": 0
    },
    "difficulty": "0x400",
    "gasLimit": "2100000",
    "alloc": {
        "e2e7f3b19889d7a3ada2afaf80b6e4e2b2f8fd35": { "balance": "30000000000000000000000" }
    }
}

2: then execute geth init command:

build/bin/geth --rpc --rpcport "8080" --rpccorsdomain "*" --datadir "./dev/data0" --port "30303" --nodiscover --rpcapi "db,eth,net,web3"
--networkid 1 init ./dev/genesis.json

Hope it helps~

Answer 2

Edited answer as questioner wants to connect to parity nodes.

Maybe this is more useful for you? Is "networkID" hex or decimal?