Dockerfile

# syntax = docker/dockerfile:1

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
# renovate: datasource=ruby-version depName=ruby
ARG RUBY_VERSION=3.3.6
FROM ruby:$RUBY_VERSION-slim as base

# Rails app lives here
WORKDIR /rails

# Set production environment
ENV BUNDLE_DEPLOYMENT="1" \
    BUNDLE_PATH="/usr/local/bundle" \
    BUNDLE_WITHOUT="development:test" \
    RAILS_ENV="production"

# Update gems and bundler
RUN gem update --system --no-document && \
    gem install -N bundler


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

# Install packages needed to build gems and node modules
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential curl libpq-dev node-gyp pkg-config python-is-python3


FROM prebuild as node

# Install JavaScript dependencies
# renovate: datasource=node-version depName=node
ARG NODE_VERSION=22.11.0
# renovate: datasource=npm depName=yarn versioning=npm
ARG YARN_VERSION=1.22.22
ENV PATH=/usr/local/node/bin:$PATH
RUN curl -sL https://github.com/nodenv/node-build/archive/master.tar.gz | tar xz -C /tmp/ && \
    /tmp/node-build-master/bin/node-build "${NODE_VERSION}" /usr/local/node && \
    npm install -g yarn@$YARN_VERSION && \
    rm -rf /tmp/node-build-master

# Install node modules
COPY --link package.json yarn.lock ./
RUN yarn install --frozen-lockfile


FROM prebuild as build

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

# Copy node modules
COPY --from=node /rails/node_modules /rails/node_modules
COPY --from=node /usr/local/node /usr/local/node
ENV PATH=/usr/local/node/bin:$PATH

# Copy application code
COPY --link . .

# 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 curl nginx postgresql-client ruby-foreman && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# configure nginx
RUN gem install foreman && \
    sed -i 's|pid /run|pid /rails/tmp/pids|' /etc/nginx/nginx.conf && \
    sed -i 's/access_log\s.*;/access_log \/dev\/stdout;/' /etc/nginx/nginx.conf && \
    sed -i 's/error_log\s.*;/error_log \/dev\/stderr info;/' /etc/nginx/nginx.conf

COPY <<-"EOF" /etc/nginx/sites-available/default
server {
  listen 3000 default_server;
  listen [::]:3000 default_server;
  access_log /dev/stdout;

  root /rails/public;

  location /cable {
    proxy_pass http://localhost:8082/cable;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
    proxy_set_header Host $host;
  }

  location / {
    try_files $uri @backend;
  }

  location @backend {
    proxy_pass http://localhost:3001;
    proxy_set_header Host $http_host;
  }
}
EOF

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

# 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 && \
    chown 1000:1000 /var/lib/nginx /var/log/nginx/* && \
    chown -R 1000:1000 db log storage tmp
USER 1000:1000

# Deployment options
ENV PORT="3001"

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

# Build a Procfile for production use
COPY <<-"EOF" /rails/Procfile.prod
nginx: /usr/sbin/nginx -g "daemon off;"
rails: ./bin/rails server -p 3001
EOF

# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["foreman", "start", "--procfile=Procfile.prod"]