在 Ropsten 网络上部署智能合约

Question

I am trying to deploy a test contract on Ropsten network. I am using metamask, infura and truffle to create and test the contract. My folder structure looks like this

My migration file has following codes

const TestContract = artifacts.require("TestContract");

module.exports = function(deployer) {
  deployer.deploy(TestContract);
};

When i run truffle migrate i am getting following error Could not find artifacts for Migrations from any sources

My truffle-config.js look like this

    const HDWalletProvider = require('truffle-hdwallet-provider')
module.exports = {
    networks: {
        ropsten: {
            provider: function() {
                return new HDWalletProvider("Mnemonic key", "https://ropsten.infura.io/v3/API_KEY")
            },
            network_id: 3,
            gas: 4000000
        }
    },
    contracts_directory: './src/contracts/',
    contracts_build_directory: './src/abis/',
    compilers: {
        solc: {
            optimizer: {
                enabled: true,
                runs: 200
            }
        }
    }
}

Answer 1

You need to have Migrations contract in your contracts folder:

pragma solidity >=0.4.25 <0.6.0;

contract Migrations {
  address public owner;
  uint public last_completed_migration;

  modifier restricted() {
    if (msg.sender == owner) _;
  }

  constructor() public {
    owner = msg.sender;
  }

  function setCompleted(uint completed) public restricted {
    last_completed_migration = completed;
  }

  function upgrade(address new_address) public restricted {
    Migrations upgraded = Migrations(new_address);
    upgraded.setCompleted(last_completed_migration);
  }
}

Also a 1_initial_migration.js in your migrations folder:

const Migrations = artifacts.require("Migrations");

module.exports = function(deployer) {
  deployer.deploy(Migrations);
};