example Dockerfile for MRSK

# Dockerfile
# syntax = docker/dockerfile:1

ARG RUBY_VERSION
FROM 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="development"


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

# Install packages need to build gems and node modules
RUN apt-get update -qq && \
    apt-get install -y build-essential curl default-libmysqlclient-dev git libpq-dev libvips node-gyp pkg-config python-is-python3

# Install JavaScript dependencies
ARG NODE_VERSION=16.19.0
ARG YARN_VERSION=1.22.19

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 application gems
COPY --link .ruby-version ./

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


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

# Copy application code
COPY --link . .

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

ARG RAILS_MASTER_KEY
ENV RAILS_MASTER_KEY=$RAILS_MASTER_KEY

# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN ./bin/rails assets:precompile


# Final stage for app image
FROM base

RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y default-mysql-client libsqlite3-0 libvips postgresql-client && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Run and own the application files as a non-root user for security
RUN useradd rails
USER rails:rails

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

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

# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]