beacon contract

beacon.example.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts/proxy/beacon/BeaconProxy.sol";
import "@openzeppelin/contracts/proxy/beacon/UpgradeableBeacon.sol";


contract Vaultv1 is Initializable {

    string public name;
    uint256 public vaLue;

    error Down(string reason);

    function initialize(string memory _name, uint256 _vaLue) public initializer {
        name = _name;
        vaLue = _vaLue;
    }

    function down() public {
        if (vaLue == 0) revert Down("!vaLue");
        vaLue--;
    }

}

contract Vaultv2 is Initializable {

    string public name;
    uint256 public vaLue;
    
    error Down(string reason);

    function initialize(string memory _name, uint256 _vaLue) public initializer {
        name = _name;
        vaLue = _vaLue;
    }

    function down() public {
        if (vaLue == 0) revert Down("!vaLue");
        vaLue--;
    }

    function up() public {
        vaLue++;
    }

}

contract VaultBeacon {

    UpgradeableBeacon immutable beacon;
    
    address public vLogic;

    constructor(address _vLogic) {
        beacon = new UpgradeableBeacon(_vLogic);
        vLogic = _vLogic;
    }

    function update(address _vLogic) public {
        beacon.upgradeTo(_vLogic);
        vLogic = _vLogic;
    }

    function implementation() public view returns(address) {
        return beacon.implementation();
    }

}

contract Factory {

    mapping(uint256 => address) private vaults;

    VaultBeacon immutable beacon;

    constructor(address _vLogic) {
        beacon = new VaultBeacon(_vLogic);
    }

    function create(string calldata _name, uint256 _vaLue, uint256 x) external returns (address) {
        BeaconProxy proxy = new BeaconProxy(address(beacon), 
            abi.encodeWithSelector(Vaultv1(address(0)).initialize.selector, _name, _vaLue)
        );
        vaults[x] = address(proxy);
        return address(proxy);
    }

    function getImplementation() public view returns (address) {
        return beacon.implementation();
    }

     function getBeacon() public view returns (address) {
        return address(beacon);
    }

     function getVault(uint256 x) public view returns (address) {
        return vaults[x];
    }


}

https://www.youtube.com/watch?v=2oUHr8hxzBA

A simple demo showing upgrading contract with beacon

• First deploy Vaultv1 and get address, e.g., 0xvault1
• Deploy Factory and use 0xvault1 as constructor argument
• To create a vault, call Factory#create(vaultname, value, idx) to set name and value and index of the vault
• To access the vault as Vaultv1, call Factory#getVault(idx) to get the vault address and invoke the method in Vaultv1 from this address
• To update the vault to Vaultv2, first deploy Vaultv2 to 0xvault2
• Call Factory#getBeacon() to get the beacon address and invoke the VaultBeacon#update(v2Address) to use Vaultv2