Dockerfile

# syntax = docker/dockerfile:1

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.4.1
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="test:development" \
    PUPPETEER_SKIP_CHROMIUM_DOWNLOAD=true \
    CHROME_BIN=/usr/bin/chromium \
    PUPPETEER_EXECUTABLE_PATH=/usr/bin/chromium \
    CHROME_PATH=/usr/bin/chromium \
    CHROME_NO_SANDBOX=true

# Throw-away build stage to reduce size of final image
FROM base as build

# Install packages needed to build gems, Chromium, ffmpeg, and headless dependencies
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y \
    build-essential \
    git \
    pkg-config \
    curl \
    chromium \
    chromium-sandbox \
    ffmpeg \
    fonts-liberation \
    libasound2 \
    libatk-bridge2.0-0 \
    libatk1.0-0 \
    libatspi2.0-0 \
    libcups2 \
    libdbus-1-3 \
    libdrm2 \
    libgbm1 \
    libgtk-3-0 \
    libnspr4 \
    libnss3 \
    libwayland-client0 \
    libyaml-dev \
    libxcomposite1 \
    libxdamage1 \
    libxfixes3 \
    libxkbcommon0 \
    libxrandr2 \
    xdg-utils \
    libxshmfence1 \
    && \
    chmod 4755 /usr/lib/chromium/chrome-sandbox && \
    # Clean up
    rm -rf /var/lib/apt/lists/* && \
    rm -rf /var/cache/apt/archives/*

# Install specific version of bundler
ARG BUNDLER_VERSION=2.6.3
RUN gem install bundler --no-document -v "${BUNDLER_VERSION}"

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

# Final stage for app image
FROM base

# Install Chromium, ffmpeg, and dependencies in the final stage
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y \
    chromium \
    chromium-sandbox \
    ffmpeg \
    fonts-liberation \
    libasound2 \
    libatk-bridge2.0-0 \
    libatk1.0-0 \
    libatspi2.0-0 \
    libcups2 \
    libdbus-1-3 \
    libdrm2 \
    libgbm1 \
    libgtk-3-0 \
    libnspr4 \
    libnss3 \
    libwayland-client0 \
    libxcomposite1 \
    libxdamage1 \
    libxfixes3 \
    libxkbcommon0 \
    libxrandr2 \
    xdg-utils \
    libxshmfence1 \
    && \
    chmod 4755 /usr/lib/chromium/chrome-sandbox && \
    # Clean up
    rm -rf /var/lib/apt/lists/* && \
    rm -rf /var/cache/apt/archives/*

# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle

# Copy application code
COPY . .

# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/

# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
    chown -R rails:rails log tmp
USER rails:rails

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

# Start the server by default, this can be overwritten at runtime
CMD ["bundle", "exec", "dotenv", "sidekiq"]