FROM postgres:alpine

RUN set -x \
	&& apk update && apk add ca-certificates curl \
	&& curl -L https://github.com/prodrigestivill/go-cron/releases/download/v0.0.8/go-cron-linux-amd64-static.gz | zcat > /usr/local/bin/go-cron \
	&& chmod a+x /usr/local/bin/go-cron \
	&& apk del ca-certificates

ENV POSTGRES_DB **None**
ENV POSTGRES_DB_FILE **None**
ENV POSTGRES_HOST **None**
ENV POSTGRES_PORT 5432
ENV POSTGRES_USER **None**
ENV POSTGRES_USER_FILE **None**
ENV POSTGRES_PASSWORD **None**
ENV POSTGRES_PASSWORD_FILE **None**
ENV POSTGRES_EXTRA_OPTS '-Z9'
ENV SCHEDULE '@daily'
ENV BACKUP_DIR '/backups'
ENV BACKUP_KEEP_DAYS 7
ENV BACKUP_KEEP_WEEKS 4
ENV BACKUP_KEEP_MONTHS 6
ENV HEALTHCHECK_PORT 8080

COPY backup.sh /backup.sh

VOLUME /backups

ENTRYPOINT ["/bin/sh", "-c"]
CMD ["exec /usr/local/bin/go-cron -s \"$SCHEDULE\" -p \"$HEALTHCHECK_PORT\" -- /backup.sh"]

HEALTHCHECK --interval=5m --timeout=3s \
  CMD curl -f "http://localhost:$HEALTHCHECK_PORT/" || exit 1