FROM alpine:3.19

# zstd for compression, tzdata so cron fires at correct local time
RUN apk add --no-cache zstd tzdata

COPY compress.sh /usr/local/bin/compress.sh
RUN chmod +x /usr/local/bin/compress.sh

# Install crontab: run compress at 02:00 every night
RUN echo "0 2 * * * /usr/local/bin/compress.sh > /proc/1/fd/1 2>&1" \
    | crontab -

# crond -f: foreground (required for containers)
# crond -l 2: log level warning and above
CMD ["crond", "-f", "-l", "2"]