FROM debian:bookworm-slim

# install oostfix and OpenDKIM
RUN apt-get update && apt-get install -y \
    postfix \
    opendkim \
    opendkim-tools \
    mailutils \
    ca-certificates \
    netcat-openbsd \
    && rm -rf /var/lib/apt/lists/*

# create OpenDKIM paths
RUN mkdir -p /etc/opendkim/keys && \
    chown -R opendkim:opendkim /etc/opendkim && \
    chmod 700 /etc/opendkim/keys

# copy config
COPY postfix-main.cf /etc/postfix/main.cf
COPY opendkim.conf /etc/opendkim.conf
COPY entrypoint.sh /entrypoint.sh

RUN chmod +x /entrypoint.sh

EXPOSE 25

HEALTHCHECK --interval=30s --timeout=10s --start-period=10s --retries=3 \
    CMD echo "QUIT" | nc -w 5 localhost 25 | grep -q "220" || exit 1

ENTRYPOINT ["/entrypoint.sh"]