e-book

truffle-config.js

const HDWalletProvider = require('@truffle/hdwallet-provider');
const { readFileSync } = require('fs');
const path = require('path');

module.exports = {
  
  networks: {
    
    ganache: {
      host: "127.0.0.1",
      port: 7545,
      network_id: "*" // matching any network id
    },

    ropsten: {
      provider: () => {

        try {

          const fileContents = 
                readFileSync(path.join(__dirname, 'secret.json'), 'utf8')
          const data = JSON.parse(fileContents);
          const privateKey = data.mnemonic;
          // Your project id, which we copied from Infura.io
          const infuraProjectId = data.infuraProjectToken;
          const rpcUrl = `https://ropsten.infura.io/v3/${infuraProjectId}`;
          const ropstenAccountId = 0;
          /*
          If we skip the last argument in the HDWalletProvider constructor, 
          by default, the account in charge of 
          the smart contract deployment will be 
          the first one generated by the mnemonic.
          If we pass in a specific index, 
          it'll use that address instead (the index is zero-based).
          */
          // How many addresses in wallet should we unlock?
          // Note: This is not used for Mainnet - only for Testnet and local deployment.
          const numAddressesToUnlock = 3
          console.log('Configuring truffle to use Mnemonic provider for Ropsten.');
          
          return 
            new HDWalletProvider(privateKey, rpcUrl, ropstenAccountId, numAddressesToUnlock);
          
        } catch (err) {
          console.error('Error', err);
        }
      },
      network_id: 3,     // Ropsten network id
      
      //Default gas limit in Truffle is 4712388 (gas limit for Homestead release).
      // This exceeds Ropsten's limit. Make sure to set a gas limit to 4700000. 
      // Otherwise, you will see the following error. Error: exceeds block gas limit
      gas: 4700000,
    },
    
  },

  // Configure your compilers
  compilers: {
    solc: {
      // version: "0.5.12", Fetch exact version from solc-bin 
      // (default: truffle's version
      settings: {          
        optimizer: {
          enabled: true,
          runs: 200
        },

       }
    }
  }
}