truffle-config.js

const fs = require('fs');
require('dotenv').config();

const HDWalletProvider = require('@truffle/hdwallet-provider');
const infuraKey = process.env.infuraKey;
const mnemonic = process.env.mnemonic;
module.exports = {

  networks: {
    // Useful for testing. The `development` name is special - truffle uses it by default
    // if it's defined here and no other network is specified at the command line.
    // You should run a client (like ganache-cli, geth or parity) in a separate terminal
    // tab if you use this network and you must also set the `host`, `port` and `network_id`
    // options below to some value.
    //

    ganache: {
      host: "127.0.0.1", // Localhost (default: none)
      port: 7545, // Standard Ethereum port (default: none)
      network_id: "*", // Any network (default: none)
    },
    development: {
      host: "127.0.0.1", // Localhost (default: none)
      port: 8545, // Standard Ethereum port (default: none)
      network_id: "*", // Any network (default: none)
    },
    develop: {
      host: "127.0.0.1", // Localhost (default: none)
      port: 8545, // Standard Ethereum port (default: none)
      network_id: "*", // Any network (default: none)
      gas: 8500000, // Gas sent with each transaction (default: ~6700000)
      gasPrice: 20000000000, // 20 gwei (in wei) (default: 100 gwei)
    },

    // Another network with more advanced options...
    // advanced: {
    // port: 8777,             // Custom port
    // network_id: 1342,       // Custom network
    // gas: 8500000,           // Gas sent with each transaction (default: ~6700000)
    // gasPrice: 20000000000,  // 20 gwei (in wei) (default: 100 gwei)
    // from: <address>,        // Account to send txs from (default: accounts[0])
    // websockets: true        // Enable EventEmitter interface for web3 (default: false)
    // },

    // Useful for deploying to a public network.
    // NB: It's important to wrap the provider as a function.
    ropsten: {
      provider: () => new HDWalletProvider(mnemonic, `https://ropsten.infura.io/v3/` + infuraKey),
      network_id: 3, // Ropsten's id
      gas: 5500000, // Ropsten has a lower block limit than mainnet
      confirmations: 2, // # of confs to wait between deployments. (default: 0)
      timeoutBlocks: 20000, // # of blocks before a deployment times out  (minimum/default: 50)
      skipDryRun: true, // Skip dry run before migrations? (default: false for public nets )
      port: 8545
    },

    rinkeby: {
      provider: () => new HDWalletProvider(mnemonic, `https://rinkeby.infura.io/v3/` + infuraKey),
      network_id: 4,
      gas: 6500000,
      skipDryRun: true
    },
    kovan: {
      provider: () => new HDWalletProvider(mnemonic, `https://kovan.infura.io/v3/` + infuraKey),
      network_id: 42,
      gas: 5500000,
      skipDryRun: true
    },
    mainnet: {
      provider: () => new HDWalletProvider(mnemonic, `https://mainnet.infura.io/v3/` + infuraKey),
      network_id: 1,
      gas: 5500000,
      skipDryRun: true
    },
    // Useful for private networks
    // private: {
    // provider: () => new HDWalletProvider(mnemonic, `https://network.io`),
    // network_id: 2111,   // This network is yours, in the cloud.
    // production: true    // Treats this network as if it was a public net. (default: false)
    // }
  },
  compilers: {
    solc: {
      version: "0.5.17",
      settings: { // See the solidity docs for advice about optimization and evmVersion
        optimizer: {
          enabled: true,
          runs: 200
        },
        //   evmVersion: "istanbul"
      }
    }
  },
  plugins: [
    'truffle-plugin-verify'
  ],
  api_keys: {
    etherscan: process.env.ETHERSCAN_API_KEY
  }
};