Dockerfile

FROM ruby:2.6.5
MAINTAINER dxw <rails@dxw.com>

# install base packages
RUN apt-get update -y -q2 \
  && apt-get upgrade -y -q2 \
  && apt-get -y -q2 install \
    nodejs \
  && apt-get -y -q2 clean

# create application user
RUN addgroup --gid 999 --quiet app \
  && adduser --gid 999 --uid 999 --quiet --disabled-password app

# set rails environment
ARG RAILS_ENV
ENV RAILS_ENV=${RAILS_ENV:-production}
ENV RACK_ENV=${RAILS_ENV:-production}

# create and use application home
ENV APP_NAME team-dashboard
ENV APP_PATH /srv/team-dashboard
COPY docker-entrypoint.sh .
RUN mkdir -p $APP_PATH
WORKDIR $APP_PATH

# bundle ruby gems to create a static dependency tree
USER app
ENV GEM_PATH /usr/local/bundle
RUN gem install --quiet bundler

USER root
COPY Gemfile $APP_PATH/Gemfile
COPY Gemfile.lock $APP_PATH/Gemfile.lock
RUN chown -R app:app $APP_PATH

ARG GITHUB_TOKEN
ARG BUNDLE_GITHUB__COM=${GITHUB_TOKEN}:x-oauth-basic

USER app
# bundle ruby gems based on the current environment, default to production
RUN \
  if [ "$RAILS_ENV" = "production" ]; then \
    bundle install --without development test --jobs 25 --retry 3; \
  else \
    bundle install --jobs 25 --retry 3; \
  fi

USER root

# add project files
COPY . $APP_PATH

# compile assets for production
RUN SECRET_KEY_BASE=dummy bundle exec rake assets:precompile
RUN mkdir -p tmp/pids

# make app own the project files
RUN chown -R app:app $APP_PATH

# run application as the app user
USER app

# expose public assets as a volume, this needs to happen after any changes to the filesystem
VOLUME ["/srv/team-dashboard/public"]

EXPOSE 3000
CMD ["bundle", "exec", "puma"]