add Docker container with cron job and mailsending

Author: JM-Lemmi

grades-docker/Dockerfile

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+#get vpn client
+FROM ghcr.io/jm-lemmi/anyconnect-simple
+
+# install python and package
+RUN apk --upgrade add git python
+RUN pip install git+https://github.com/TINF21CS1/python-campusnet
+
+# Add crontab
+COPY grades.sh /app/grades.sh
+RUN crontab -l /cron
+RUN echo "0 7-23 * * * /app/grades.sh" >> /cron
+RUN crontab /cron
+RUN rm /cron
+
+#ENV USERNAME "s:)@student.dhbw-mannheim.de"
+#ENV PASSWORD='***'
+#ENV NOTIFY_RECIPIENT="***"
+#default values for dhbw mannheim
+ENV AUTHGROUP Studenten
+ENV HOST drogon.dhbw-mannheim.de
+
+# add sendmail
+RUN apk add ssmtp
+
+COPY entrypoint.sh /app/entrypoint.sh
+CMD /bin/bash /app/entrypoint.sh

grades-docker/cron.sh

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+#!/bin/bash
+ 
+python3 -m campusnet $USERNAME $PASSWORD -o table > /tmp/grades.txt
+if [ ! -s grades.txt ]; then
+    mv /tmp/grades.txt grades.txt
+    exit 0
+fi
+/usr/bin/diff grades.txt /tmp/grades.txt > /tmp/diff.txt
+if [ -s /tmp/diff.txt ]; then
+    (echo -e 'Subject: Grades changed\n\n'; cat /tmp/diff.txt; echo -e '\n\nAll grades:\n'; cat /tmp/grades.txt) | /usr/sbin/sendmail $NOTIFY_RECIPIENT
+fi
+mv /tmp/grades.txt grades.tx

grades-docker/entrypoint.sh

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+#! /bin/bash
+
+# https://stackoverflow.com/a/39296583
+# sets noficy_recipient to username, if not set
+if [[ -z "${NOTIFY_RECIPIENT}" ]]; then
+  NOTIFY_RECIPIENT="${USERNAME}"
+fi
+
+crond
+echo "$(date +"%b %d %H:%M:%S") $HOSTNAME entrypoint.sh[$$]: Started crond."
+echo $PASSWORD | openconnect -b --user=$USERNAME --authgroup=$AUTHGROUP --passwd-on-stdin $HOST
+echo "$(date +"%b %d %H:%M:%S") $HOSTNAME entrypoint.sh[$$]: Started openconnect."
+echo -e "root=${USERNAME}\nmailhub=studgate.dhbw-mannheim.de:25\nrewriteDomain=student.dhbw-mannheim.de\nhostname=${hostname}\nAuthUser=${USERNAME}\nAuthPass=${PASSWORD}\nAuthMethod=LOGIN\nFromLineOverride=no" > /etc/ssmtp/ssmtp.conf
+echo -e "root:${USERNAME}:studgate.dhbw-mannheim.de:25"
+chfn -f 'Campusnet Grades' root
+echo "$(date +"%b %d %H:%M:%S") $HOSTNAME entrypoint.sh[$$]: Updates ssmtp configuration."
+
+echo "$(date +"%b %d %H:%M:%S") $HOSTNAME start.sh[$$]: ➔ Switching to log output from 'grep CRON /var/log/syslog'"
+tail -f grep CRON /var/log/syslog