start.sh
```shell
#!/bin/sh
while [ true ]; do
socat TCP-LISTEN:2200,fork,reuseaddr EXEC:'./chall'
done;
```
Dockerfile
```
FROM ubuntu:24.04@sha256:7c06e91f61fa88c08cc74f7e1b7c69ae24910d745357e0dfe1d2c0322aaf20f9 AS chroot
RUN apt-get update && \
apt-get --assume-yes --no-install-recommends install socat && \
apt-get clean && \
rm -rf /var/lib/apt/lists/*
COPY ./app /app
WORKDIR /app
RUN chmod +x chall
CMD sh start.sh
```