start_testnet.sh

#!/usr/bin/env bash

# Based on https://medium.com/@chim/ethereum-how-to-setup-a-local-test-node-with-initial-ether-balance-using-geth-974511ce712
# Initialise a local geth testnet with automine

CHAIN_DIRECTORY=~/.testnet;
STARTING_BALANCE="0x5337000000000000000000"

if [ -d "$CHAIN_DIRECTORY" ]; then
    rm -r ${CHAIN_DIRECTORY}
fi

mkdir -p ${CHAIN_DIRECTORY}/data
mkdir -p ${CHAIN_DIRECTORY}/config
mkdir -p ${CHAIN_DIRECTORY}/logs
touch ${CHAIN_DIRECTORY}/logs/00.log

cat > ${CHAIN_DIRECTORY}/config/genesis.json <<EOL
{
  "config": {
    "chainId": 99,
    "homesteadBlock": 0,
    "eip155Block": 0,
    "eip158Block": 0
  },
  "nonce": "0x0000000000000042",
  "timestamp": "0x0",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "gasLimit": "0x8000000",
  "difficulty": "0x400",
  "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "coinbase": "0x3333333333333333333333333333333333333333",
  "alloc": {
    "0x2e18Dba2a20913Be8901F7b054879eAbE8968009": {
      "balance": "${STARTING_BALANCE}"
    },
    "0x14f05dAcA8A6459C41C13075B256BBa839f380e5": {
      "balance": "${STARTING_BALANCE}"
    },
    "0xD2D6a3ebb71855a2b9e5e7e91e45576c3254d349": {
      "balance": "${STARTING_BALANCE}"
    },
    "0x68DaEBa874308c6a74f3E39Be1Da73f289054074": {
      "balance": "${STARTING_BALANCE}"
    },
    "0x81379704e1662c05a8E7ACC2Cec25C12e5989eA5": {
      "balance": "${STARTING_BALANCE}"
    }
  }
}
EOL

geth \
    --identity "LocalTestnet" \
    --rpc \
    --rpcport 8545 \
    --rpccorsdomain "*" \
    --datadir ${CHAIN_DIRECTORY}/data/ \
    --port 30303 \
    --nodiscover \
    --rpcapi db,eth,net,web3,personal \
    --networkid 99 \
    --maxpeers 0 \
    --verbosity 6 \
    init ${CHAIN_DIRECTORY}/config/genesis.json 2>> ${CHAIN_DIRECTORY}/logs/00.log

cp -r "$(pwd)/keystore" ${CHAIN_DIRECTORY}/data

geth \
    --port 38545 \
    --mine\
    --minerthreads=1 \
    --rpc \
    --rpcport 8545 \
    --rpccorsdomain "*" \
    --datadir ${CHAIN_DIRECTORY}/data/ \
    --port 30303 \
    --nodiscover \
    --rpcapi web3,eth,net,debug,personal \
    --networkid 99