truffle.js

const homedir = require('homedir')
const path = require('path')

const HDWalletProvider = require('truffle-hdwallet-provider')
const HDWalletProviderPrivkey = require('truffle-hdwallet-provider-privkey')

const DEFAULT_MNEMONIC = 'stumble story behind hurt patient ball whisper art swift tongue ice alien'

const defaultRPC = (network) =>
    `https://${network}.infura.io`

const configFilePath = (filename) =>
    path.join(homedir(), `.aragon/${filename}`)

const mnemonic = () => {
    try {
        return require(configFilePath('mnemonic.json')).mnemonic
    } catch (e) {
        return DEFAULT_MNEMONIC
    }
}

const settingsForNetwork = (network) => {
    try {
        return require(configFilePath(`${network}_key.json`))
    } catch (e) {
        return { }
    }
}

// Lazily loaded provider
const providerForNetwork = (network) => (
    () => {
        let { rpc, keys } = settingsForNetwork(network)

        rpc = rpc || defaultRPC(network)

        if (!keys || keys.length == 0) {
            return new HDWalletProvider(mnemonic(), rpc)
        }

        return new HDWalletProviderPrivkey(keys, rpc)
    }
)

const mochaGasSettings = {
    reporter: 'eth-gas-reporter',
    reporterOptions : {
        currency: 'USD',
        gasPrice: 3
    }
}

const mocha = process.env.GAS_REPORTER ? mochaGasSettings : {}

module.exports = {
    networks: {
        rpc: {
            network_id: "*",
            host: 'localhost',
            port: 8545,
            gas: 6.9e6,
            gasPrice: 15000000001
        },
        devnet: {
            network_id: 16,
            host: 'localhost',
            port: 8535,
            gas: 6.9e6,
            gasPrice: 15000000001
        },
        mainnet: {
            network_id: 1,
            provider: providerForNetwork('mainnet'),
            gas: 7.9e6,
            gasPrice: 3000000001
        },
        ropsten: {
            network_id: 3,
            provider: providerForNetwork('ropsten'),
            gas: 4.712e6
        },
        rinkeby: {
            network_id: 4,
            provider: providerForNetwork('rinkeby'),
            gas: 6.9e6,
            gasPrice: 15000000001
        },
        kovan: {
            network_id: 42,
            provider: providerForNetwork('kovan'),
            gas: 6.9e6
        },
        coverage: {
            host: "localhost",
            network_id: "*",
            port: 8555,
            gas: 0xffffffffff,
            gasPrice: 0x01
        },
        development: {
            host: 'localhost',
            network_id: '*',
            port: 8545,
            gas: 6.9e6,
            gasPrice: 15000000001
        },
    },
    build: {},
    mocha,
    solc: {
        optimizer: {
            enabled: true,
            runs: 10000
        }
    },
    compilers: {
        solc: {
            version: "0.4.24", // A version or constraint - Ex. "^0.5.0".
                               // Can also be set to "native" to use a native solc
            // docker: true,   // Use a version obtained through docker
            settings: {
                // See the solidity docs for advice about optimization and evmVersion
                // https://solidity.readthedocs.io/en/v0.5.12/using-the-compiler.html#setting-the-evm-version-to-target
                optimizer: {
                    enabled: true,
                    runs: 10000   // Optimize for how many times you intend to run the code
                }
                // evmVersion: <string>   // Default: "petersburg"
            }
        }
    }
}