Dockerfile

ARG RUBY_VERSION=4.0.1
ARG NODE_VERSION=22.7.0

# Use Node image so we can pull the binaries from here.
FROM node:$NODE_VERSION AS node

# Ruby build image.
FROM ruby:${RUBY_VERSION}-slim AS base

# Setup environment variables.
ENV WORK_ROOT=/src
ENV APP_HOME=$WORK_ROOT/app
ENV LANG=C.UTF-8
ENV BUNDLE_PATH=$APP_HOME/vendor/bundle

# Set prod environment to avoid installing dev dependencies
ENV BUNDLE_WITHOUT=development:test
ENV BUNDLE_DEPLOYMENT=1
ENV RAILS_ENV=production
ENV NODE_ENV=production

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

RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential libssl-dev libpq-dev git libsasl2-dev libyaml-dev curl && \
    rm -rf /var/lib/apt/lists/*

# Copy node binaries from node image.
COPY --from=node /usr/local /usr/local
COPY --from=node /opt /opt

# Create app directory.
RUN mkdir -p "${APP_HOME}"

# Setup work directory.
WORKDIR $APP_HOME

# Copy dependencies files and install libraries.
COPY --link Gemfile Gemfile.lock package.json yarn.lock .yarnrc.yml .ruby-version ./

RUN corepack enable
RUN gem install bundler && bundle install -j 4 && yarn install --immutable && \
    bundle exec bootsnap precompile --gemfile && \
    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git

# 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 ./bin/rails assets:precompile

# Build runtime image.
FROM base

# Install packages needed for deployment
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y curl libpq-dev libvips libjemalloc2 libyaml-dev && \
    apt-get clean && rm -rf /var/lib/apt/lists/*

ENV USERNAME=rails_api_base
ENV USER_UID=1000
ENV USER_GID=1000

# Create a rootless user.
RUN groupadd --gid "$USER_GID" "$USERNAME" && \
    useradd --uid "$USER_UID" --gid "$USER_GID" -m "$USERNAME"

# Create app directory.
RUN mkdir -p "${APP_HOME}" && chown -R "$USERNAME:$USERNAME" "$APP_HOME" && chmod -R 700 "$APP_HOME"

# Change to the rootless user.
USER "$USERNAME"

# Setup work directory.
WORKDIR "$APP_HOME"

# Copy everything from the builder image
COPY --chown="$USERNAME:$USERNAME" . .
COPY --from=builder --chown="$USERNAME:$USERNAME" "$APP_HOME/public/" "$APP_HOME/public/"
COPY --from=builder --chown="$USERNAME:$USERNAME" "$APP_HOME/tmp/" "$APP_HOME/tmp/"
COPY --from=builder --chown="$USERNAME:$USERNAME" "$APP_HOME/vendor/" "$APP_HOME/vendor/"

# Set permissions (700 for security) and create symlink
# Note: Permissions set via RUN instead of COPY --chmod for Heroku compatibility
USER root
RUN chmod -R 700 "$APP_HOME"
RUN ln -s /usr/lib/*-linux-gnu/libjemalloc.so.2 /usr/lib/libjemalloc.so.2
USER "$USERNAME"

# Deployment options
ENV RAILS_LOG_TO_STDOUT=true
ENV RAILS_SERVE_STATIC_FILES=true
ENV LD_PRELOAD=/usr/lib/libjemalloc.so.2

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

# Start the server by default, this can be overwritten at runtime
EXPOSE 3000

CMD ["bundle", "exec", "puma", "-C", "config/puma.rb"]