Added cron to the Dockerfile as temporary fix until we have periodic file scanning in the backend

docker/Dockerfile

@@ -1,3 +1,14 @@
+
+# This file is used to build the Dockerhub image. To host pyShelf yourself for 
+# production, please use the official pyShelf image on 
+# https://hub.docker.com/r/pyshelf/pyshelf
+
+# Use the following commands to build and push the docker image to Dockerhub:
+#
+#   docker build -t pyshelf/pyshelf -f .\docker\Dockerfile .
+#   docker login
+#   docker push pyshelf/pyshelf
+
 FROM ubuntu
 
 EXPOSE 8000
@@ -5,22 +16,27 @@ EXPOSE 8000
 RUN apt-get update -y
 RUN DEBIAN_FRONTEND=noninteractive apt-get install -y build-essential python3 python3-dev python3-pip python3-venv nginx-full
 
-COPY . /pyshelf
-
-WORKDIR /pyshelf/
-RUN python3 -m pip install -r requirements.txt
+RUN DEBIAN_FRONTEND=noninteractive apt-get install -y cron
+RUN echo "* * * * * cd /pyshelf/ && python3 importBooks >> /var/log/cron.log 2>&1" > import_books_scheduler.cron && crontab import_books_scheduler.cron
 
 COPY ./docker/pyshelf_nginx.conf /etc/nginx/sites-available/pyshelf_nginx.conf
 RUN ln -s /etc/nginx/sites-available/pyshelf_nginx.conf /etc/nginx/sites-enabled/
 
+COPY . /pyshelf
+COPY ./docker/config.json /pyshelf/config.json
+
 WORKDIR /pyshelf/
-ENTRYPOINT cd src/ \
+RUN python3 -m pip install -r requirements.txt
+
+WORKDIR /pyshelf/
+ENTRYPOINT cron start \
+            && python3 configure \
+            && cd src/ \
             && python3 manage.py makemigrations \
             && python3 manage.py makemigrations interface \
             && python3 manage.py migrate \
             && python3 manage.py migrate interface \
             && cd .. \
-            && python3 configure \
             && python3 importBooks \
             && nginx -g "daemon on;" \
             && uwsgi --ini uwsgi.ini