ARG RUBY_VERSION=3.3.1 FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim as base # Rails app lives here WORKDIR /rails # Set production environment ENV RAILS_ENV="production" \ BUNDLE_DEPLOYMENT="1" \ BUNDLE_PATH="/usr/local/bundle" \ BUNDLE_WITHOUT="development" # Throw-away build stage to reduce size of final image FROM base as build # Install packages needed to build gems RUN apt-get update -qq && \ apt-get install --no-install-recommends -y build-essential curl git libpq-dev libvips pkg-config # Copy application code COPY . . # Install application gems RUN bundle install && \ rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \ bundle exec bootsnap precompile --gemfile # Precompile bootsnap code for faster boot times RUN bundle exec bootsnap precompile app/ lib/ # Precompiling assets for production without requiring secret RAILS_MASTER_KEY RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile # Final stage for app image FROM base # Install packages needed for deployment RUN apt-get update -qq && \ apt-get install --no-install-recommends -y libvips postgresql-client curl && \ rm -rf /var/lib/apt/lists /var/cache/apt/archives # Copy built artifacts: gems, application COPY --from=build /usr/local/bundle /usr/local/bundle COPY --from=build /rails /rails # Run and own only the runtime files as a non-root user for security RUN useradd rails --home /rails --shell /bin/bash && \ chown -R rails:rails db log storage tmp USER rails:rails # Entrypoint prepares the database. ENTRYPOINT ["/rails/bin/docker-entrypoint"] # Start the server by default, this can be overwritten at runtime EXPOSE 3000 CMD ["./bin/rails", "server"]