anchor.diff:  
   # global environment settings
   ENV ANSIBLE_TOWER_VER=latest \
  -ADMIN_PASSWORD=changme \
  +ADMIN_PASSWORD=changeme \
   SERVER_NAME=localhost
   
   ADD ./inventory /opt/inventory
  -ADD ./tower_setup_conf.yml /opt/tower_setup_conf.yml
   
   RUN \
    apt-get -y update && \
  
positive.code:  rm -rf ansible-tower-setup-${ANSIBLE_TOWER_VER}.tar.gz && \
   mv ansible-tower-setup-* /opt/tower-setup && \
   mv /opt/inventory /opt/tower-setup/inventory && \ 
   mv /opt/tower_setup_conf.yml /opt/tower-setup/tower_setup_conf.yml && \
  
  # add passwords and fix locale issue
   sed -i "s/changeme/${ADMIN_PASSWORD}/g" /opt/tower-setup/inventory && \
  
negative.code: 
  # set runtime (from ybalt/ansible-tower)
  ADD docker-entrypoint.sh /docker-entrypoint.sh
  RUN chmod +x /docker-entrypoint.sh
  ENTRYPOINT ["/docker-entrypoint.sh"]
  CMD ["ansible-tower"]
  