Dockerfile

# syntax = docker/dockerfile:1

# Define Ruby version
ARG RUBY_VERSION=3.3.4
FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base

WORKDIR /rails

# Install base packages
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y curl libjemalloc2 libvips postgresql-client && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Set environment for production
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 build essentials
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential git libpq-dev pkg-config && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Install gems
COPY Gemfile Gemfile.lock ./
RUN bundle install && \
    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
    bundle exec bootsnap precompile --gemfile

# Copy application code and precompile assets
COPY . .

RUN bundle exec bootsnap precompile app/ lib/

RUN chmod +x bin/* && \
    sed -i "s/\r$//g" bin/* && \
    sed -i 's/ruby\.exe$/ruby/' bin/*

# Temporarily set SECRET_KEY_BASE for assets precompilation
RUN SECRET_KEY_BASE=a618e99253e4917e90a9ffab04df5565189e072eca3e32fa91ac0f2baffcb4e0541224f5bbc20f46417eed61a3e326488eacb190c3609682f34f3354f3f3dc1e ./bin/rails assets:precompile

# Final stage for app image
FROM base

# Copy built artifacts
COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
COPY --from=build /rails /rails

# Setup non-root user and permissions
RUN groupadd --system --gid 1000 rails && \
    useradd rails --uid 1000 --gid 1000 --create-home --shell /bin/bash && \
    chown -R rails:rails db log storage tmp
USER 1000:1000

# Entrypoint for database setup
ENTRYPOINT ["/rails/bin/docker-entrypoint"]

# Start the server
EXPOSE 3000
CMD ["./bin/rails", "server"]