private-blockchain

private-blockchain

the point of this repo is to document how to setup a private ethereum block-chain for development purposes.

setup

For this you will need to install geth

create a folder

$ mkdir privatenetwork

initialize command

Now we initialize the genesis block that will use the config we just created:

$ geth --datadir privatenetwork init genesis.json

run javascript console

Then we run the geth console:

$ geth --datadir privatenetwork console --networkid 100

view admin output

Now we can dump the admin info for the server - NOTE - make sure you can see the > meaning we are in the console:

> admin
{
  datadir: "/Users/kai/projects/private-blockchain/privatenetwork/privatenetwork",
  nodeInfo: {
    enode: "enode://07c25495068df19102c0e2a62f9e5b183becb12893a5b3316fb41270c5d6bb9773397ff09454e13f6b18bcac518e8e745df28e090bf87c43fb5641390d394c9a@[::]:30303",
    id: "07c25495068df19102c0e2a62f9e5b183becb12893a5b3316fb41270c5d6bb9773397ff09454e13f6b18bcac518e8e745df28e090bf87c43fb5641390d394c9a",
    ip: "::",
    listenAddr: "[::]:30303",
    name: "Geth/v1.7.0-stable-6c6c7b2a/darwin-amd64/go1.9",
    ports: {
      discovery: 30303,
      listener: 30303
    },
    protocols: {
      eth: {
        difficulty: 400,
        genesis: "0xa7aac261cc19872089526fb17580ac6406bda1326cb86f9a9c04eae4b8ba86f5",
        head: "0xa7aac261cc19872089526fb17580ac6406bda1326cb86f9a9c04eae4b8ba86f5",
        network: 1
      }
    }
  },
  peers: [],
  addPeer: function(),
  exportChain: function(),
  getDatadir: function(callback),
  getNodeInfo: function(callback),
  getPeers: function(callback),
  importChain: function(),
  removePeer: function(), 
  sleep: function github.com/ethereum/go-ethereum/console.(*bridge).Sleep-fm(),
  sleepBlocks: function github.com/ethereum/go-ethereum/console.(*bridge).SleepBlocks-fm(),
  startRPC: function(),
  startWS: function(),
  stopRPC: function(),
  stopWS: function()
}

check block number

Type the following into the console to ensure we are starting with zero blocks:

> eth.blockNumber
0

run geth server

Run a single geth server on ONE node:

$ geth --datadir privatenetwork --networkid 100

This will have created a listening server running on 127.0.0.1:30303

You can test this:

$ telnet 127.0.0.1 30303

Grab the UDP listener up line and copy the enode://XXX@[::]:30303 line.

Find out your local ip address ($ ifconfig | grep 192) - and replace [::] with that ip:

e.g. here is a bootnode address:

enode://165ec598b922a9ab8b195a098afe2524fecd8b23edb758ceeca064299d72b4c037f504af84f2cbec494094f23734ca0490dc9e4b437efe92efee261423625e04@192.168.0.35:30303

This is used to created the geth command to be run on the other nodes using the --bootnodes flag - for example:

$ geth --datadir privatenetwork --networkid 100 --bootnodes enode://165ec598b922a9ab8b195a098afe2524fecd8b23edb758ceeca064299d72b4c037f504af84f2cbec494094f23734ca0490dc9e4b437efe92efee261423625e04@192.168.0.35:30303

You can join multiple nodes by using a CSV value for --bootnodes:

$ geth --datadir privatenetwork --networkid 100 --bootnodes enode://4325e709245171b5062e5d01ff015988ab58b08910988d0f5b6455402d2878a4fa3112cd0e2b74630de669778355a889821b2f9489d82d99df5770e6b7699abf@192.168.0.69:30303,enode://a6ec0b75d1db77b0f408b5c9e1ec3e1841de4d36951370b3e0913e4c3710a8849a26e2b56f25efa0cf6f89e10b715fa0989bafdeb51a405426f9911a602aa888@192.168.0.43:30303,enode://bdc6fe600013a786c2cb3471e00d7e03351e9433349ebbde13af13b8fe5836e38aa8995c78f33184cd566a0c903ec473b284d69dc1309ab94ea1c579c0ffd8c1@192.168.0.12:30303

attach to running geth server

If you have a geth server already running - here is how to attach to it:

$ geth attach ipc:geth.ipc

mining

In the console, create a personal account with:

$ personal.newAccount('password')

check your account is here:

$ eth.accounts

set your account for mining:

$ miner.setEtherbase(eth.accounts[0])

start mining with defined number of threads:

$ miner.start(2)

check hashrate:

$ miner.getHashrate()

get the address of the last miner who mined a block:

$ eth.getBlock(eth.blockNumber).miner

geth --datadir privatenetwork --networkid 100 --bootnodes enode://d5ca08c309ce34d5e91337dd244d04446a494762d8af684c0f4c896630118a57c0f4b54d4b6534b437ed3c895ebca88835e7bcefcf9edcf1704b90c13295e27b@192.168.0.42:30303 --unlock 0xbe74344e18d96d2b0ea67f6cfbdd333b3a1bb853 --rpc --rpcapi "eth,net,web3" --rpccorsdomain '*' --rpcaddr localhost --rpcport 8545