Dockerfile

############################################
### Base image ###
############################################
# Image which will be used for all environments: production, testing & development
ARG RUBY_VERSION=2.7.2
FROM ruby:$RUBY_VERSION-slim-buster as base
ARG PG_MAJOR=12
ARG DEBIAN_FRONTEND=noninteractive

COPY .seatrain/Aptfile /tmp/Aptfile

RUN apt-get update -qq \
  && apt-get dist-upgrade -y \
  && apt-get install -yq --no-install-recommends \
  curl \
  git \
  gnupg2 \
  && curl -sSL https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - \
  && echo 'deb http://apt.postgresql.org/pub/repos/apt/ stretch-pgdg main' $PG_MAJOR > /etc/apt/sources.list.d/pgdg.list \
  && apt-get update -qq \
  && apt-get install -yq --no-install-recommends \
  libpq5 \
  postgresql-client-$PG_MAJOR \
  $(cat /tmp/Aptfile | xargs) \
  && apt-get purge -y curl \
  && apt-get clean \
  && rm -rf /var/cache/apt/archives/* \
  && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
  && truncate -s 0 /var/log/*log

ARG BUNDLER_VERSION
ENV BUNDLER_VERSION=${BUNDLER_VERSION:-2.2.5}
ENV GEM_HOME=/usr/local/bundle
ENV BUNDLE_PATH=$GEM_HOME
ENV BUNDLE_APP_CONFIG=$BUNDLE_PATH
ENV BUNDLE_BIN=/usr/local/bin
ENV BUNDLE_JOBS=4
ENV BUNDLE_RETRY=3

ENV LANG=C.UTF-8

ENV PATH /app/bin:$PATH

RUN groupadd --gid 1001 lewagon \
  && useradd --uid 1001 --gid lewagon --shell /bin/bash --create-home lewagon

# Upgrade RubyGems and install required Bundler version
RUN gem update --system && \
  rm -f /usr/local/bin/ruby/gems/*/specifications/default/bundler-*.gemspec && \
  gem install bundler -v $BUNDLER_VERSION

# to chown this dir even before it will be brought by COPY
# to be able to write into it during yarn install
RUN mkdir /app \
  && chown -R lewagon:lewagon /app

WORKDIR /app

################################################################################
### Builder. Adds node and Yarn. Not necessary in production. ###
###############################################################################
# Image which has all development dependencies and which will build the production bundle

FROM base as builder
ARG NODE_MAJOR=14
ARG YARN_VERSION=1.22.5
ARG DEBIAN_FRONTEND=noninteractive

RUN apt-get update -qq \
  && apt-get install -yq --no-install-recommends \
  build-essential \
  curl \
  libpq-dev \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
  && truncate -s 0 /var/log/*log

# Add NodeJS to sources list
RUN curl -sL https://deb.nodesource.com/setup_$NODE_MAJOR.x | bash -

# Add Yarn to the sources list
RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add - \
  && echo 'deb http://dl.yarnpkg.com/debian/ stable main' > /etc/apt/sources.list.d/yarn.list

# Install Nodejs & Yarn
RUN apt-get update -qq \
  && apt-get install -yq --no-install-recommends \
  nodejs \
  yarn=$YARN_VERSION-1 \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
  && truncate -s 0 /var/log/*log

################################################################
# Development image
################################################################
FROM builder as development
# Install Chromium and configure for VNC
RUN curl -sSL https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - \
  && echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list \
  && apt-get update -qq \
  && apt-get -yq dist-upgrade \
  && apt-get install -yq --no-install-recommends \
  fluxbox \
  google-chrome-stable \
  wmctrl \
  x11vnc \
  xfce4-terminal \
  xvfb \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
  && truncate -s 0 /var/log/*log

########################################################
# Node and Bundle for production
######################################################## 
FROM builder as prod_gems_and_assets

COPY --chown=lewagon:lewagon ./Gemfile /app/Gemfile
COPY --chown=lewagon:lewagon ./Gemfile.lock /app/Gemfile.lock
COPY --chown=lewagon:lewagon package.json /app/
COPY --chown=lewagon:lewagon yarn.lock /app/
COPY --chown=lewagon:lewagon . /app


RUN bundle config set --local clean 'true' \
  && bundle config set --local without 'development test' \
  && bundle install

RUN yarn install \
  && (rm -rf /tmp/* || true)

ENV RAILS_ENV=production

ARG RAILS_MASTER_KEY
RUN bundle exec rails assets:precompile \
  && yarn cache clean \
  && (rm -rf /tmp/* || true) \
  # Cleanup
  && rm -rf $BUNDLE_PATH/*.gem \
  && find $BUNDLE_PATH/ruby -name "*.c" -delete \
  && find $BUNDLE_PATH/ruby -name "*.o" -delete \
  # TODO: ADD COMMENT
  && find $BUNDLE_PATH/ruby -name ".git"  -type d -prune -execdir rm -rf {} +

# https://github.com/rubygems/rubygems/issues/3225
RUN rm -rf /usr/local/bundle/ruby/*/cache

################################################################
# Deployable image
################################################################
FROM base as deploy
# Copy prebuilt gems
COPY --chown=lewagon:lewagon --from=prod_gems_and_assets $BUNDLE_PATH $BUNDLE_PATH

COPY --chown=lewagon:lewagon . /app
# Copy prebuilt assets
COPY --chown=lewagon:lewagon --from=prod_gems_and_assets /app/public/assets /app/public/assets
COPY --chown=lewagon:lewagon --from=prod_gems_and_assets /app/public/packs /app/public/packs

USER lewagon

ENV RAILS_ENV=production
ENV RACK_ENV=production
ENV NODE_ENV=production
ENV RAILS_LOG_TO_STDOUT=enabled
ENV RAILS_SERVE_STATIC_FILES=enabled