link app.db to /config

Dockerfile

@@ -16,7 +16,7 @@ RUN apt-get install -y imagemagick libmagickwand-dev
 RUN groupadd -g 999 appuser && \
     useradd -r -u 999 -g appuser appuser
 
-RUN mkdir -p /app /ebooks
+RUN mkdir -p /app /ebooks /config
 WORKDIR /app
 
 # copy calibre-web to /app
@@ -37,6 +37,9 @@ COPY policy.xml /etc/ImageMagick-6/policy.xml
 # fix some permissions
 RUN chown -R appuser /app
 
+# symlink calibre-web config
+RUN ln -s /config/app.db /app/app.db
+
 EXPOSE 8083/tcp
 USER appuser
 CMD python cps.py