anchor.diff:  #
   # https://github.com/ibbd/dockerfile-nginx
   #
  +# 先创建目录：sudo mkdir /var/lib/nginx
   
   # Pull base image.
   FROM ibbd/dockerfile-ubuntu
  
positive.code:   apt-get update && \
    apt-get install -y nginx && \
    rm -rf /var/lib/apt/lists/* && \
    echo "\ndaemon off;" >> /etc/nginx/nginx.conf && \
    chown -R www-data:www-data /var/lib/nginx
  
  # Define mountable directories.
  VOLUME ["/etc/nginx/sites-enabled", "/etc/nginx/certs", "/etc/nginx/conf.d", "/var/log/nginx", "/var/www/html"]
  
negative.code: # Expose ports.
  EXPOSE 80
  EXPOSE 443
  
  