truffle.js

const HDWalletProvider = require('truffle-hdwallet-provider');
const fs               = require('fs');

// first read in the secrets.json to get our mnemonic
let secrets;
let mnemonic;
if (fs.existsSync('secrets.json')) {
  secrets = JSON.parse(fs.readFileSync('secrets.json', 'utf8'));
  mnemonic = secrets.mnemonic;
} else {
  console.log('no secrets.json found. You can only deploy to the testrpc.');
  mnemonic = '';
}

module.exports = {
  networks: {
    development: {
      host      : 'localhost',
      port      : 8545,
      network_id: '*', // Match any network id
    },
    kovan      : {
      provider  : new HDWalletProvider(mnemonic, 'https://kovan.infura.io'),
      network_id: '*',
      gas       : 4500000,
      gasPrice  : 25000000000,
    },
    rinkeby    : {
      provider  : new HDWalletProvider(mnemonic, 'https://rinkeby.infura.io'),
      network_id: '*',
      gas       : 4500000,
      gasPrice  : 25000000000,
    },
    ropsten    : {
      provider  : new HDWalletProvider(mnemonic, 'https://ropsten.infura.io'),
      network_id: '*',
      gas       : 4500000,
      gasPrice  : 25000000000,
    },
    mainnet    : {
      provider  : new HDWalletProvider(mnemonic, 'https://mainnet.infura.io'),
      network_id: 1,
      gas       : 4500000,
      gasPrice  : 4000000000,
    },
  },
};