anchor.diff:  ADD configure-db.php /configure-db.php
   ADD supervisord.conf /etc/supervisor/conf.d/supervisord.conf
   RUN sed -i "s/PHP_VERSION/${PHP_VERSION}/" /etc/supervisor/conf.d/supervisord.conf
  -CMD php /configure-db.php && supervisord -c /etc/supervisor/conf.d/supervisord.conf
  +CMD php /configure-db.php && php update.php --update-schema=force-yes && supervisord -c /etc/supervisor/conf.d/supervisord.conf
positive.code: RUN ln -s /etc/nginx/sites-available/ttrss /etc/nginx/sites-enabled/ttrss
  RUN rm /etc/nginx/sites-enabled/default
  
  # install ttrss
  WORKDIR /var/www
  RUN rm -rf *
  RUN git clone https://git.tt-rss.org/fox/tt-rss.git .
  
  # expose only nginx HTTP port
  EXPOSE 80
  
  # set default settings
  ENV TTRSS_SELF_URL_PATH="http://localhost"
  
negative.code: # set configuration to look at Docker ENV variables
  ADD config.docker.php config.php
  
  # set permissions on directories
  RUN chown www-data:www-data -R /var/www && \ 
      chmod -R 777 ${TTRSS_CACHE_DIR}/images && \
  