truffle-config.js

const path = require("path");

const HDWalletProvider = require("@truffle/hdwallet-provider");

// Set up infura api key
const infuraKey = "90c5f3148b7840109319eed40c9bec57";

const fs = require("fs");

// Import the private key for the account for the smart contract
const privateKey = fs.readFileSync(".secret").toString().trim();

module.exports = {
  // See <http://truffleframework.com/docs/advanced/configuration>
  // to customize your Truffle configuration!
  contracts_build_directory: path.join(__dirname, "client/src/contracts"),
  networks: {
    development: {
      host: "127.0.0.1",
      port: 7545,
      network_id: "*",
    },
    rinkeby: {
      provider: () =>
        new HDWalletProvider(
          privateKey,
          `https://rinkeby.infura.io/v3/${infuraKey}`
        ),
      network_id: 4, // rinkeby's id
      gas: 4500000, // rinkeby has a lower block limit than mainnet
      gasPrice: 21000000000,
      networkCheckTimeout: 1000000,
    },
  },
  compilers: {
    solc: {
      version: "0.4.24",
      settings: {
        optimizer: {
          enabled: true,
          runs: 200,
        },
      },
    },
  },
};