Dockerfile

FROM jsurf/rpi-raspbian:latest

RUN [ "cross-build-start" ]

ENV LANG C.UTF-8
ENV TZ Europe/Berlin

# add our user and group first to make sure their IDs get assigned consistently, regardless of whatever dependencies get added
RUN groupadd -r mysql && useradd -r -g mysql mysql

# add gosu for easy step-down from root
ENV GOSU_VERSION 1.10
RUN set -x \
	&& apt-get update && apt-get install -y --no-install-recommends ca-certificates wget && rm -rf /var/lib/apt/lists/* \
	&& wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture)" \
	&& wget -O /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture).asc" \
	&& export GNUPGHOME="$(mktemp -d)" \
	&& gpg --keyserver ha.pool.sks-keyservers.net --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 \
	&& gpg --batch --verify /usr/local/bin/gosu.asc /usr/local/bin/gosu \
	&& rm -rf "$GNUPGHOME" /usr/local/bin/gosu.asc \
	&& chmod +x /usr/local/bin/gosu \
	&& gosu nobody true \
	&& apt-get purge -y --auto-remove ca-certificates wget

RUN mkdir /docker-entrypoint-initdb.d

# install "pwgen" for randomizing passwords
RUN apt-get update && apt-get install -y --no-install-recommends \
		pwgen \
	&& rm -rf /var/lib/apt/lists/*

# the "/var/lib/mysql" stuff here is because the mysql-server postinst doesn't have an explicit way to disable the mysql_install_db codepath besides having a database already "configured" (ie, stuff in /var/lib/mysql/mysql)
# also, we set debconf keys to make APT a little quieter
RUN { \
		echo mariadb-server mysql-server/root_password password 'unused'; \
		echo mariadb-server mysql-server/root_password_again password 'unused'; \
	} | debconf-set-selections \
	&& apt-get update \
	&& apt-get install -y \
		mariadb-server \
	&& rm -rf /var/lib/apt/lists/* \
# comment out any "user" entires in the MySQL config ("docker-entrypoint.sh" or "--user" will handle user switching)
	&& sed -ri 's/^user\s/#&/' /etc/mysql/my.cnf /etc/mysql/conf.d/* \
# purge and re-create /var/lib/mysql with appropriate ownership
	&& rm -rf /var/lib/mysql && mkdir -p /var/lib/mysql /var/run/mysqld \
	&& chown -R mysql:mysql /var/lib/mysql /var/run/mysqld \
# ensure that /var/run/mysqld (used for socket and lock files) is writable regardless of the UID our mysqld instance ends up having at runtime
	&& chmod 777 /var/run/mysqld

# comment out a few problematic configuration values
RUN 	find /etc/mysql/ -name '*.cnf' -print0 \
		| xargs -0 grep -lZE '^(bind-address|log|user\s)' \
		| xargs -rt -0 sed -Ei 's/^(bind-address|log|user\s)/#&/'; \
# don't reverse lookup hostnames, they are usually another container
	echo '[mysqld]\nskip-host-cache\nskip-name-resolve' > /etc/mysql/conf.d/docker.cnf
	
RUN [ "cross-build-end" ]

VOLUME ["/var/lib/mysql"]

COPY docker-entrypoint.sh /usr/local/bin/
ENTRYPOINT ["docker-entrypoint.sh"]

EXPOSE 3306
CMD ["mysqld"]