Deploying Smart Contracts with Metamask and Truffle
In this article, we’ll walk through the process of deploying smart contracts using Metamask and Truffle on a Ropsten test network. We’ll also address an issue you may encounter when trying to migrate your contract.
Prerequisites
- Node.js (LTS or latest)
- Truffle CLI (
npm install -g truffle)
- Metamask wallet
Step 1: Create a new project and configure your settings
Create a new directory for your project and initialize it with truffle init. Add the following configuration to your metamask.js file:
const Metamask = require('metamask');
module.exports = {
// Your account name (e.g., "your_account")
mnemonic: "YourMnemonicWord",
// The network you want to use
network: {
ropsten,
},
// The password for your Metamask wallet (this will be used as a key for the contract)
password: "",
};
Step 2: Create a new smart contract
Create a new file called contract.js and add the following code:
const Web3 = require('web3');
const Web3Contract = require('web3-ethereum-contracts');
class MySmartContract {
constructor() {
this.web3 = new Web3(new Web3.providers.HttpProvider('
const contractAddress = '0xYourContractAddress';
const contractabi = {"version": "1", "name": "MyContract", "functions": ["myFunction"]};
this.contracts = new Web3Contract(this.web3, contractAddress, contractabi);
}
myFunction() {
// Call the function you want to deploy
console.log("Hello from myFunction!");
}
}
module.exports = MySmartContract;
Step 3: Compile and deploy your smart contract
Create a new file called compile.js and add the following code:
const Truffle = require('truffle');
module.exports = {
compile() {
return new Trufflesolid();
},
};
Step 4: Use Truffle to migrate your contract from Ropsten
Run the following command in your terminal:
npm run compile
This will create a compiled version of your smart contract. Then, use Truffle to migrate it from Ropsten:
truffle migrate --network ropsten
Step 5: Update your Metamask account
Update your metamask.js file with the following configuration:
const Metamask = require('metamask');
const ropstenAddress = "0xYourRopstenAccount";
const ropstenPassword = "";
module.exports = {
mnemonic: ropstenPassword,
network: {
ropsten: {
address: ropstenAddress,
password: ropstenPassword,
},
},
};
Step 6: Deploy your contract using Metamask
Update your metamask.js file with the following configuration:
const Metamask = require('metamask');
const ropstenAddress = "0xYourRopstenAccount";
const ropstenPassword = "";
module.exports = {
mnemonic: ropstenPassword,
network: {
ropsten: {
address: ropstenAddress,
password: ropstenPassword,
},
},
};
Error message
When you run truffle migrate --network ropsten, you should get an error similar to this:
npm run compile
This is because the compiled version of your contract does not include any metadata that Truffle requires for deployment.
Solution
To fix this issue, you need to update your compiled contract to include the required metadata. You can do this by adding the following code to your compile.js file:
“`javascript
const Web3Contract = require(‘web3-ethereum-contracts’);
class MySmartContract {
constructor() {
const web3 = new Web3(new Web3.providers.HttpProvider(‘
this.