Dockerfile to build sslh container

Dockerfile.sslh

FROM ubuntu:18.04 as base
RUN apt update && \
  apt upgrade -y && \
  apt install -y libc6 libcap2 libconfig9 libwrap0 \
  debconf init-system-helpers adduser lsb-base update-inetd

FROM base as build
RUN apt install -y libwrap0-dev libconfig-dev libpcre3-dev git
RUN git clone https://github.com/yrutschle/sslh.git
RUN cd sslh && \
  git checkout v1.20 && \
  make && DESTDIR=/tmp/sslh make install && \
  mkdir /tmp/sslh/etc && \
  cp basic.cfg /tmp/sslh/etc/sslh.cfg

FROM base
COPY --from=build /tmp/sslh/ /
RUN apt clean && rm -rf /var/lib/apt/lists/*

ENTRYPOINT []