truffle-config.js

require('babel-register');
require('babel-polyfill');
require('dotenv').config();
// const HDWalletProvider = require('truffle-hdwallet-provider-privkey');
const HDWalletProvider = require('@truffle/hdwallet-provider');
const privateKeys = process.env.PRIVATE_KEYS || '';

module.exports = {
  networks: {
    development: {
      host: '127.0.0.1',
      port: 7545,
      network_id: '*', // Match any network id
    },
    kovan: {
      provider: function () {
        return new HDWalletProvider(
          privateKeys.split(','), // Array of account private keys
          `https://kovan.infura.io/v3/${process.env.INFURA_API_KEY}` // Url to an Ethereum Node
        );
      },
      gas: 5000000,
      gasPrice: 5000000000, // 5 gwei
      network_id: 42,
    },
    main: {
      provider: function () {
        return new HDWalletProvider(
          privateKeys.split(','), // Array of account private keys
          `https://main.infura.io/v3/${process.env.INFURA_API_KEY}` // Url to an Ethereum Node
        );
      },
      gas: 5000000,
      gasPrice: 5000000000, // 5 gwei
      network_id: 1,
    },
    rinkeby: {
      provider: function () {
        return new HDWalletProvider(
          privateKeys.split(','), // Array of account private keys
          `https://rinkeby.infura.io/v3/${process.env.INFURA_API_KEY}` // Url to an Ethereum Node
        );
      },
      gas: 5000000,
      gasPrice: 5000000000, // 5 gwei
      network_id: 4,
    },
    // rinkeby: {
    //   provider: function () {
    //     return new HDWalletProvider(
    //       privateKeys.split(','), // Array of account private keys
    //       `https://rinkeby.infura.io/v3/${process.env.INFURA_API_KEY}` // Url to an Ethereum Node
    //     );
    //   },
    //   gas: 5000000,
    //   gasPrice: 5000000000, // 5 gwei
    //   network_id: 4,
    // },
    ropsten: {
      provider: function () {
        return new HDWalletProvider(
          privateKeys.split(','), // Array of account private keys
          `https://ropsten.infura.io/v3/${process.env.INFURA_API_KEY}` // Url to an Ethereum Node
        );
      },
      gas: 5000000,
      gasPrice: 5000000000, // 5 gwei
      network_id: 3,
    },
  },
  contracts_directory: './src/contracts/',
  contracts_build_directory: './src/abis/',
  compilers: {
    solc: {
      version: '>=0.6.0 <0.8.0',
      optimizer: {
        enabled: true,
        runs: 200,
      },
    },
  },
};