Generate genesis block with n number of prefilled accounts

genesis-generator.js

import bip39 from "bip39";
import hdWallet from "ethereumjs-wallet/hdkey";
import cluster from "cluster";
import fs from "fs";
const ETH_PATH = "m/44'/60'/0'/0";
const NUM_CPUS = 8;
const NUM_ACCOUNTS_PER_CORE = 200000;
const mnemonic =
  "source pitch chronic mother need ghost unable asset supreme tragic else interest asset eagle update rule slim elder adapt next emerge trash doctor fun";
const seed = bip39.mnemonicToSeed(mnemonic);
const wallet = hdWallet.fromMasterSeed(seed);
const genesisFile = {
  config: {
    chainId: 15,
    homesteadBlock: 0,
    eip155Block: 0,
    eip158Block: 0
  },
  difficulty: "20",
  gasLimit: "2100000",
  alloc: {}
};
const cleanup = () => {
  fs.writeFile(
    "./sample-genesis.json",
    JSON.stringify(genesisFile, null, 2),
    err => {
      if (err) {
        return console.log(err);
      }
    }
  );
};
let received = 0;
if (cluster.isMaster) {
  for (var i = 0; i < NUM_CPUS; i++) {
    const worker_env = {
      start: NUM_ACCOUNTS_PER_CORE * i,
      limit: NUM_ACCOUNTS_PER_CORE
    };
    const proc = cluster.fork(worker_env);
    proc.on("message", message => {
      if (message === "done") proc.kill(0);
      else {
        received++;
        if (received % 1000 === 0) console.log(received);
        genesisFile.alloc[message] = { balance: "30000000000000000000" };
        if (received > NUM_ACCOUNTS_PER_CORE * NUM_CPUS - 1) cleanup();
      }
    });
  }
} else {
  const worker_env = process.env;
  for (
    var i = parseInt(worker_env.start);
    i < parseInt(worker_env.start) + parseInt(worker_env.limit);
    i++
  ) {
    process.send(
      wallet
        .derivePath(ETH_PATH)
        .deriveChild(i)
        .getWallet()
        .getAddressString()
        .replace("0x", "")
    );
  }
  process.send("done");
}