docker-postsrsd/Dockerfile

FROM alpine:3.15.4

ARG POSTSRSD_PACKAGE_VERSION=1.11-r0
RUN adduser -S postsrsd \
    && apk add --no-cache postsrsd=$POSTSRSD_PACKAGE_VERSION \
    && mkdir -p /etc/postsrsd/secrets \
    && chown postsrsd /etc/postsrsd/secrets

USER postsrsd

VOLUME /etc/postsrsd/secrets

# https://github.com/roehling/postsrsd/blob/1.6/postsrsd.c#L342
ENV SRS_DOMAIN change-me.tld
ENV SRS_SECRET /etc/postsrsd/secrets/list

# forward SRS lookup
EXPOSE 10001/tcp
# reverse SRS lookup
EXPOSE 10002/tcp

# > Cannot open file with secret: /etc/postsrsd/secrets/list
CMD set -x; \
    if [ ! -f "$SRS_SECRET" ]; \
        then tr -dc '1-9a-zA-Z' < /dev/random | head -c 32 > "$SRS_SECRET"; \
    fi \
    && postsrsd -l0.0.0.0 -e