Requirements

• lang: Rust (backend) + Svelte (Frontend) + Solidity (Smart Contract)
• stack: AWS EC2 + MongoDB + Ganache + MetaMask

export LOTTERY_DB="private mongodb addr"
export LOTTERY_EC2="private ec2 addr"
export GANACHE="ganache addr"

ubuntu:~$ cd backend && rustup override set nightly && cargo run --release

ubuntu:~$ cd frontend && yarn install && yarn dev --host

ubuntu:~$ truffle migrate --network dev

Frontend

• Svelte
• ViteJS

Backend

• Rust actix-rs
• Rust kakao-rs
• MongoDB

Limitations

• Cannot run ChainLink VRF v2 to use provably fair RNG
  • However, our implementation is hard to exploit as we generate the lottery number when the admin clicks the Pick Winner button.
  • On the call, it generates on the fly and sends money right away. No one can see the number before the game finishes.
  • The estimated gas fee to call of this library is about $4.