Dockerfile

# syntax=docker/dockerfile:1
# check=error=true

# This Dockerfile is designed for production, not development. Use with Kamal or build'n'run by hand:
# docker build -t antique_analyzer .
# docker run -d -p 80:80 -e RAILS_MASTER_KEY=<value from config/master.key> --name antique_analyzer antique_analyzer

# For a containerized dev environment, see Dev Containers: https://guides.rubyonrails.org/getting_started_with_devcontainer.html

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
ARG RUBY_VERSION=3.4.4
FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base

# Rails app lives here
WORKDIR /rails

# Install base packages
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y\
    curl libjemalloc2 libvips sqlite3 nodejs npm && \
    ln -s /usr/lib/$(uname -m)-linux-gnu/libjemalloc.so.2 /usr/local/lib/libjemalloc.so && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Set production environment variables and enable jemalloc for reduced memory usage and latency.
ENV RAILS_ENV="production" \
    BUNDLE_DEPLOYMENT="0" \
    BUNDLE_PATH="/usr/local/bundle" \
    BUNDLE_WITHOUT="development" \
    LD_PRELOAD="/usr/local/lib/libjemalloc.so"

# 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 git libyaml-dev pkg-config && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Install application gems
COPY Gemfile Gemfile.lock vendor ./

RUN bundle install && \
    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
    # -j 1 disable parallel compilation to avoid a QEMU bug: https://github.com/rails/bootsnap/issues/495
    bundle exec bootsnap precompile -j 1 --gemfile

# Copy application code
COPY . .

# Make bin scripts executable
RUN chmod +x bin/*

# Precompile bootsnap code for faster boot times.
# -j 1 disable parallel compilation to avoid a QEMU bug: https://github.com/rails/bootsnap/issues/495
RUN bundle exec bootsnap precompile -j 1 app/ lib/

# NOTE: BuildKit secret mounts are not available in all build environments
# (for example, Hugging Face Spaces). To keep builds portable we skip
# precompiling assets at build-time here and instead perform a best-effort
# assets precompile at container start. This makes the image buildable
# on Spaces without requiring BuildKit secret support.

# Final stage for app image
FROM base

# Run and own only the runtime files as a non-root user for security
RUN groupadd --system --gid 1000 rails && \
    useradd rails --uid 1000 --gid 1000 --create-home --shell /bin/bash
USER 1000:1000

# Copy built artifacts: gems, application
COPY --chown=rails:rails --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
COPY --chown=rails:rails --from=build /rails /rails

# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]

# Start server - all startup logic handled by bin/start.sh
EXPOSE 7860
CMD ["./bin/start.sh"]