truffle-config.js

module.exports = {
  networks: {

    development: {
     host: "127.0.0.1",       // Localhost (default: none)
     port: 8777,              // Standard Ethereum port (default: none)
     network_id: "23",        // Any network (default: none)
    },

    mainnet: {
      host: 'localhost',
      port: 8545,
      network_id: '1',
      skipDryRun: true,
      confirmations: 0,
      gasPrice: 5000000000,   // 5 gwei
      gas: 2523835,
    },

    rinkeby: {
      host: 'localhost',
      port: 8545,
      network_id: '4',
      skipDryRun: true,
      confirmations: 0,
      gasPrice: 3000000000,   // 3 gwei
      gas: 3000000,
    },

    // 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/${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: 200,  // # of blocks before a deployment times out  (minimum/default: 50)
      // skipDryRun: true     // Skip dry run before migrations? (default: false for public nets )
    },

    // 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)
    }
  },

  // Set default mocha options here, use special reporters etc.
  mocha: {
    // timeout: 100000
  },

  // Configure your compilers
  compilers: {
    solc: {
      // version: "0.5.1",    // Fetch exact version from solc-bin (default: truffle's version)
      // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
      // settings: {          // See the solidity docs for advice about optimization and evmVersion
      //  optimizer: {
      //    enabled: false,
      //    runs: 200
      //  },
      //  evmVersion: "byzantium"
      // }
    }
  }
}