anchor.diff:  ARG REVISION=master
   ENV RAILS_ENV development
   ENV GEM_HOME /opt/canvas/.gems
  +ENV YARN_VERSION 0.27.5-1
   
   # add nodejs and recommended ruby repos
   RUN apt-get update \
  
positive.code:     adduser canvasuser sudo && \
      echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
  
  RUN gem install bundler --version 1.14.6
  
  COPY assets/dbinit.sh /opt/canvas/dbinit.sh
  COPY assets/start.sh /opt/canvas/start.sh
  
negative.code:        ; do cp config/$config.yml.example config/$config.yml \
         ; done
  
  RUN $GEM_HOME/bin/bundle install --jobs 8 --without="mysql"
  RUN yarn install --pure-lockfile
  RUN COMPILE_ASSETS_NPM_INSTALL=0 $GEM_HOME/bin/bundle exec rake canvas:compile_assets_dev
  
  RUN mkdir -p log tmp/pids public/assets public/stylesheets/compiled \
      && touch Gemmfile.lock
  