Dockerfile for you to test Webpacker-enabled Rails including yarn, phantomjs on circleci v2

config.yml

version: 2
jobs:
  build:
    docker:
      - image: anonoz/ruby-2.4.1-yarn-phantomjs:0.0.2
      
      # Specify service dependencies here if necessary
      # CircleCI maintains a library of pre-built images
      # documented at https://circleci.com/docs/2.0/circleci-images/
      - image: circleci/postgres:9.6

    environment:
      - SECRET_KEY_BASE: "itdoesntmatter"
      - RAILS_ENV: "test"

    working_directory: /app

    steps:
      - checkout

      - run:
          name: copy database.yml template
          command: |
            cp config/circleci.database.yml config/database.yml

      # node_modules for webpack
      - restore_cache:
          keys:
          - yarn-cache-{{ .Branch }}-{{ checksum "yarn.lock" }}
          - yarn-cache-{{ .Branch }}
          - yarn-cache
      - run:
          name: install npm dependencies with yarn
          command: |
            yarn
      - save_cache:
          key: yarn-cache-{{ .Branch }}-{{ checksum "yarn.lock" }}
          paths:
            - ./node_modules
      - save_cache:
          key: yarn-cache-{{ .Branch }}
          paths:
            - ./node_modules
      - save_cache:
          key: yarn-cache
          paths:
            - ./node_modules

      # Ruby Dependencies
      - restore_cache:
          keys:
          - gem-cache-{{ .Branch }}-{{ checksum "Gemfile.lock" }}
          - gem-cache-{{ .Branch }}
          - gem-cache
      - run:
          name: install ruby dependencies
          command: |
            bundle install --jobs=4 --retry=3 --path vendor/bundle
      - save_cache:
          key: gem-cache-{{ .Branch }}-{{ checksum "Gemfile.lock" }}
          paths:
            - ./vendor/bundle
      - save_cache:
          key: gem-cache-{{ .Branch }}
          paths:
            - ./vendor/bundle
      - save_cache:
          key: gem-cache
          paths:
            - ./vendor/bundle
        
      # Database setup
      - run: bundle exec rake db:create
      - run: bundle exec rake db:schema:load

      # run tests!
      - run:
          name: run tests
          command: |
            mkdir /tmp/test-results
            
            bundle exec rspec --format progress \
                            --format RspecJunitFormatter \
                            --out /tmp/test-results/rspec.xml \
                            --format progress

      - deploy:
          name: deploy limo
          command: |
            if [ "${CIRCLE_BRANCH}" == "develop" ]; then
              bundle exec cap staging deploy
            fi

      # collect reports
      - store_test_results:
          path: /tmp/test-results
      - store_artifacts:
          path: /tmp/test-results
          destination: test-results

Dockerfile

FROM ruby:2.4.1

# nodejs
RUN curl -sL https://deb.nodesource.com/setup_7.x | bash -

# yarn
RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -\
    && echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list

# finally the rest
RUN apt-get update && apt-get install -y \
  apt-transport-https \
  build-essential \
  ca-certificates \
  bzip2 \
  libfontconfig \
  curl \
  nodejs \
  yarn \
  rsync \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/*

# For feature testing
RUN mkdir /tmp/phantomjs \
    && curl -L https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-2.1.1-linux-x86_64.tar.bz2 \
           | tar -xj --strip-components=1 -C /tmp/phantomjs \
    && cd /tmp/phantomjs \
    && mv bin/phantomjs /usr/local/bin \
    && cd \
    && apt-get purge --auto-remove -y \
        curl \
    && apt-get clean \
    && rm -rf /tmp/* /var/lib/apt/lists/*

RUN mkdir -p /app
WORKDIR /app

RUN gem install bundler