truffle.js.default

const WalletProvider = require("truffle-wallet-provider")
const Wallet         = require('ethereumjs-wallet')

const development = {
	host       : '127.0.0.1',
	port       : 8545,
	network_id : 5777,
	gas        : process.env.TRUFFLE_GAS || 3 * 10**6,
	gasPrice   : process.env.TRUFFLE_GAS_PRICE || 20 * 10**9
}

const infuraAccessToken = process.env.INFURA_ACCESS_TOKEN

const infuraNetworks = ! infuraAccessToken ?
	{} :
		["ropsten", "rinkeby", "kovan", "mainnet"].reduce(
			(result, network) => {
				
				const envForPrivateKey = `${network.toUpperCase()}_PRIVATE_KEY`
				const privateKeyString = process.env[envForPrivateKey]
				
				if (privateKeyString) {
					
					const privateKey = Buffer.from(
						privateKeyString.replace('0x', ''),
						'hex'
					)
					const wallet = Wallet.fromPrivateKey(privateKey)
					const provider = new WalletProvider(
						wallet,
						`https://${network}.infura.io/${infuraAccessToken}`
					)
					
					result[network] = {
						...development,
						provider
					}
				}
				
				return result
			},
			{}
		)

module.exports = {
	rpc : development,
	networks : {
		...infuraNetworks,
		development
	},
	solc : {
		optimizer : {
			enabled : true,
			runs : 200
		}
	}
}