Decentralized Raffle

Quickstart

Requirements

• nodejs
• NPM or YARN

Installation

git clone https://github.com/PatrickAlphaC/decentralized-raffle.git
cd decentralized-raffle
yarn

Deploy contracts

npx hardhat deploy

Deploy and start a local node

npx hardhat node

Deploy to Kovan

To deploy to a testnet or a live network, you need the following environment variables:

1. KOVAN_RPC_URL=https://eth-ropsten.alchemyapi.io/v2/
2. PRIVATE_KEY=0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1

Your KOVAN_RPC_URL is the URL of your blockchain node, for example, from alchemy.

Your PRIVATE_KEY is the private key of your metamask or cryptowallet. Make sure it starts with 0x. You might have to add 0x if you're pulling the key from something like metamask.

You can set them in a file named .env. You can follow the example of .env.example of what the contents of that file will look like.

You'll also need testnet ETH and testnet LINK. You can find both here.

Once you do so, you can run:

npx hardhat deploy --network kovan

Fund your contract with LINK.

npx hardhat fund-link --contract insert-contract-address-here --network kovan

And enter your raffle

npx hardhat run scripts/enter.ts --network kovan

Add keepers

Once you deploy to Kovan, you can register your contract with the kovan keepers registry. Please follow the documentation for more information.

npx hardhat deploy --network kovan

And you can verify once you have an ETHERSCAN_API_KEY

Add this configuration in the file named .env:

ETHERSCAN_API_KEY=<YOUR ETHERSCAN KEY>

The command to verify the source code in Etherscan is:

npx hardhat verify --network mainnet DEPLOYED_CONTRACT_ADDRESS args...

The contract Raffle receives these arguments in his constructor:

        address _vrfCoordinator,
        address _linkToken,
        bytes32 _keyHash,
        uint256 _chainlinkFee,
        uint256 _entranceFee,
        uint256 _interval

Get the deploy's arguments in the file helper-hardhat-config.ts. Find the network kovan (42). Per example:

  42: {
    name: 'kovan',
    linkToken: '0xa36085F69e2889c224210F603D836748e7dC0088',
    keyHash:
      '0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4',
    vrfCoordinator: '0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9',
    chainlinkFee: '100000000000000000',
    entranceFee: '100000000000000000',
    fundAmount: '1000000000000000000',
    interval: '20'
  }

Then run this command to verify the source code in Etherscan:

npx hardhat verify --network kovan <DEPLOYED_CONTRACT_ADDRESS> <vrfCoordinator> <linkToken> <keyHash> <chainlinkFee> <entranceFee> <interval>

Tests

npx hardhat test