anchor.diff: -FROM ruby:2.2.3
  +FROM daocloud.io/library/ruby
   # docker build --no-cache=true -t jekyll:2.4.0 .
   #
   # docker run -d --privileged --name stainboy -p 80:4000 -v ~/git/stainboy.github.io:/opt/web jekyll:2.4.0
  
positive.code: 
  # EXPOSE 4000
  
  ENTRYPOINT ["jekyll", "serve", "-s", "/opt/web"]
negative.code: 
  RUN \
      # http proxy
      # export http_proxy=http://proxy.sin.sap.corp:8080 &&\
      # export https_proxy=http://proxy.sin.sap.corp:8080 &&\
      # download nodejs
      curl -sLO https://nodejs.org/dist/v4.0.0/node-v4.0.0-linux-x64.tar.gz &&\
      tar -xf /node-v4.0.0-linux-x64.tar.gz -C /opt/ &&\
  