anchor.diff:  RUN apt-get install -y build-essential nodejs && apt-get clean
   RUN gem install foreman
   
  +# This image is only intended to be able to run this app in a production RAILS_ENV
  +ENV RAILS_ENV production
  +
   ENV GOVUK_APP_NAME whitehall
   ENV GOVUK_CONTENT_SCHEMAS_PATH /govuk-content-schemas
   ENV PORT 3020
  -ENV REDIS_HOST redis
  -ENV RAILS_ENV development
   ENV DATABASE_URL mysql2://root:root@mysql/whitehall_development
  -ENV TEST_DATABASE_URL mysql2://root:root@mysql/whitehall_test
   
   ENV APP_HOME /app
   RUN mkdir $APP_HOME
  
positive.code:   GOVUK_APP_DOMAIN=www.gov.uk \
    GOVUK_WEBSITE_ROOT=www.gov.uk \
    GOVUK_APP_DOMAIN_EXTERNAL=www.gov.uk \
    RAILS_ENV=production \
    bundle exec rake shared_mustache:compile assets:precompile
  
  HEALTHCHECK CMD curl --silent --fail localhost:$PORT/healthcheck || exit 1
  
negative.code: WORKDIR $APP_HOME
  ADD Gemfile* $APP_HOME/
  ADD .ruby-version $APP_HOME/
  RUN bundle config set deployment 'true'
  RUN bundle config set without 'development test'
  RUN bundle install --jobs 4
  
  ADD . $APP_HOME
  
  