Dockerfile

FROM alpine:3.4

ARG version="0.1.0-dev"
ARG build_date="unknown"
ARG commit_hash="unknown"
ARG vcs_url="unknown"
ARG vcs_branch="unknown"

LABEL org.label-schema.vendor="Softonic" \
    org.label-schema.name="Socat" \
    org.label-schema.description="Exposes to a defined OUTPUT PORT the INPUT from a TCP endpoint." \
    org.label-schema.usage="/src/README.md" \
    org.label-schema.url="https://github.com/bvis/docker-socat/blob/master/README.md" \
    org.label-schema.vcs-url=$vcs_url \
    org.label-schema.vcs-branch=$vcs_branch \
    org.label-schema.vcs-ref=$commit_hash \
    org.label-schema.version=$version \
    org.label-schema.schema-version="1.0" \
    org.label-schema.docker.cmd.devel="" \
    org.label-schema.docker.params="IN=Input,\
OUT=Output" \
    org.label-schema.build-date=$build_date

ENV IN="172.17.0.1:4999" \
    OUT="4999"

RUN apk add --no-cache socat

ENTRYPOINT socat -d -d TCP-L:$OUT,fork TCP:$IN