# Use the official Ruby image. # https://hub.docker.com/_/ruby FROM ruby:2.5 # Install production dependencies. WORKDIR /usr/src/app COPY Gemfile Gemfile.lock ./ ENV BUNDLE_FROZEN=true RUN bundle install # Copy local code to the container image. COPY . . # Configure and document the service HTTP port. ENV PORT 8080 EXPOSE $PORT # Run the web service on container startup. CMD ["ruby", "./app.rb"]