Dockerfile.rack.erb in vps-0.2.2

- old
+ new

@@ -9,8 +9,11 @@
 
 WORKDIR /opt/app
 COPY . .
 
 ENV RACK_ENV=production
+<%- if upstream.dockerfile %>
+<%= upstream.dockerfile.strip %>
+<%- end %>
 RUN gem install bundler -v <%= upstream.bundler_version %>
 RUN bundle install --without development test
 CMD ["bundle", "exec", "rackup", "config.ru", "-o", "0.0.0.0"]