InstaContract/contracts/MoatAddress.sol

// Implement the proper governance mechanism to update the admin address like admin have rights to upgrade anything but not just "admin". Governance will be used to set admin address.

pragma solidity ^0.4.24;

contract AddressRegistry {

    event eSetAddr(string AddrName, address TargetAddr);
    mapping(bytes32 => address) internal addressBook;

    modifier onlyAdmin() {
        require(
            msg.sender == getAddr("admin"),
            "Permission Denied"
        );
        _;
    }

    constructor() public {
        addressBook[keccak256("admin")] = msg.sender;
    }

    function setAddr(string AddrName, address Addr) public onlyAdmin {
        addressBook[keccak256(AddrName)] = Addr;
        emit eSetAddr(AddrName, Addr);
    }

    function getAddr(string AddrName) public view returns(address AssignedAddress) {
        address realAddress = addressBook[keccak256(AddrName)];
        require(realAddress != address(0), "Not a valid address.");
        return realAddress;
    }

}