docker-mysqldump-sshd/Dockerfile

FROM alpine:3.12

ARG DUMB_INIT_PACKAGE_VERSION=1.2.2-r1
ARG MARIADB_CLIENT_PACKAGE_VERSION=10.4.13-r0
ARG OPENSSH_PACKAGE_VERSION=8.3_p1-r0
RUN apk add --no-cache \
        dumb-init=$DUMB_INIT_PACKAGE_VERSION \
        mariadb-client=$MARIADB_CLIENT_PACKAGE_VERSION \
        openssh-server=$OPENSSH_PACKAGE_VERSION \
    && adduser -S dump

# RUN apk add --no-cache man openssh-doc=$OPENSSH_PACKAGE_VERSION

COPY entrypoint.sh /
ENTRYPOINT ["dumb-init", "--", "/entrypoint.sh"]
COPY sshd_config /etc/ssh/sshd_config
ENV SSHD_HOST_KEYS_DIR /etc/ssh/host_keys
ENV MYSQLDUMP_ARGS --help
RUN chmod a=rx /entrypoint.sh \
    && chmod a=r /etc/ssh/sshd_config \
    && sed -i 's#^\(dump:.*\):/sbin/nologin$#\1:/tmp/mysqldump.sh#' /etc/passwd \
    && mkdir $SSHD_HOST_KEYS_DIR \
    && chown dump $SSHD_HOST_KEYS_DIR
VOLUME $SSHD_HOST_KEYS_DIR

USER dump
EXPOSE 2222/tcp
CMD ["/usr/sbin/sshd", "-D", "-e"]