FROM alpine
ARG TZ=Europe/London

RUN apk add --update socat tzdata && rm -rf /var/cache/apk/* \
 && ln -sf /usr/share/zoneinfo/$TZ /etc/localtime  \
 && echo $TZ > /etc/timezone

EXPOSE 1433
ENTRYPOINT /usr/bin/socat tcp4-listen:1433,fork tcp4-connect:$IP:1433