anchor.diff:  #                           Added environment variable for nginx config directory.
   # 2014/12/03 cgwong v0.2.1: Updated Kibana version. Switch to specific nginx version.
   # 2014/12/04 cgwong v0.2.2: Introduce more environment variables. Corrected bug in dashboard copy.
  +# 2015/01/08 cgwong v1.0.0: Added another variable.
   # ################################################################
   
   FROM dockerfile/ubuntu
  
positive.code:     apache2-utils \
      nginx=${NGINX_VERSION}
  
  # forward request and error logs to docker log collector
  RUN ln -sf /dev/stdout /var/log/nginx/access.log \
    && ln -sf /dev/stderr /var/log/nginx/error.log
  
  
negative.code: ##ENV KIBANA_VERSION 4.0.0-BETA2
  ENV KIBANA_VERSION 3.1.2
  ENV KIBANA_BASE /var/www
  ENV KIBANA_HOME ${KIBANA_BASE}/kibana
  RUN mkdir -p ${KIBANA_BASE}
  WORKDIR ${KIBANA_BASE}
  RUN wget https://download.elasticsearch.org/kibana/kibana/kibana-${KIBANA_VERSION}.tar.gz \
  