Docker Development Environment

def print_green(heredoc)
  puts set_color heredoc, :green
end

def ask_with_default(prompt, default)
  value = ask("#{prompt} [#{default}]")
  value.blank? ? default : value
end

create_file './.dockerignore', <<~EOF
.git*
db/*.sqlite3
db/*.sqlite3-journal
log/*
tmp/*
tmp/pid/server.pid
Dockerfile
README.rdoc
EOF

create_file './docker-compose.yml' do
  ruby_verison = ask_with_default("What version of Ruby do you want to use?", '2.6.6')
  node_version = ask_with_default("What version of Node do you want to use?", '13')
  bundle_version = ask_with_default("What version of Bundle do you want to use?", '2.1.4')
  postgres_version = ask_with_default("What version of Postgres do you want to use?", '12')

<<~EOF
version: '2.4'
services:
  base: &app
    build:
      context: .
      dockerfile: ./Dockerfile
      args:
        RUBY_VERSION: '#{ruby_verison}'
        NODE_MAJOR: '#{node_version}'
        BUNDLE_VERSION: '#{bundle_version}'
        PG_MAJOR: '#{postgres_version}'

    tmpfs:
      - /tmp

  backend: &backend
    <<: *app
    stdin_open: true
    tty: true
    volumes:
      - .:/app:cached
      - rails_cache:/app/tmp/cache
      - bundle:/usr/local/bundle
      - node_modules:/app/node_modules
      - packs:/app/public/packs
    environment:
      - PSQL_HISTFILE=/app/log/.psql_history
      - DATABASE_URL=postgres://postgres:postgres@postgres:5432
      - BOOTSNAP_CACHE_DIR=/bundle/bootsnap
      - WEBPACKER_DEV_SERVER_HOST=webpacker
    depends_on:
      - postgres
      - redis

  app:
    <<: *backend
    command: bundle exec rails server -b 0.0.0.0
    ports:
      - '3000:3000'

  webpacker:
    <<: *app
    command: ./bin/webpack-dev-server
    ports:
      - '3035:3035'
    volumes:
      - .:/app:cached
      - bundle:/usr/local/bundle
      - node_modules:/app/node_modules
      - packs:/app/public/packs
    environment:
      - NODE_ENV=${NODE_ENV:-development}
      - RAILS_ENV=${RAILS_ENV:-development}
      - WEBPACKER_DEV_SERVER_HOST=0.0.0.0

  sidekiq:
    <<: *backend
    command: bundle exec sidekiq -C config/sidekiq.yml

  redis:
    image: redis:latest

  postgres:
    image: postgres:#{postgres_version}
    volumes:
      - .psqlrc:/root/.psqlrc:ro
      - postgres:/var/lib/postgresql/data
      - ./log:/root/log:cached
    environment:
      - PSQL_HISTFILE=/root/log/.psql_history
    ports:
      - 5432
    healthcheck:
      test: pg_isready -U postgres -h 127.0.0.1
      interval: 5s

volumes:
  postgres:
  redis:
  bundle:
  node_modules:
  rails_cache:
  packs:
EOF
end

create_file './Dockerfile', <<~EOF
ARG RUBY_VERSION
FROM ruby:$RUBY_VERSION
LABEL [email protected]

ARG NODE_MAJOR
ARG PG_MAJOR
ARG BUNDLE_VERSION
RUN apt-get update
RUN apt-get install -y build-essential

# Add PostgreSQL to sources list
RUN curl -sSL https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - \
  && echo 'deb http://apt.postgresql.org/pub/repos/apt/ buster-pgdg main' $PG_MAJOR > /etc/apt/sources.list.d/pgdg.list

RUN curl -sL https://deb.nodesource.com/setup_$NODE_MAJOR.x | bash -

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

RUN apt-get -y update
RUN apt-get -y install nodejs
RUN apt-get -y install yarn
RUN yarn config set "strict-ssl" false

RUN bundle config --global frozen 1

COPY Gemfile Gemfile.lock ./
RUN gem install bundler -v $BUNDLE_VERSION
RUN bundle install -j $(nproc)

RUN mkdir -p /app
WORKDIR /app
EOF

print_green <<~EOF
Your application is now configured with Docker. To start running docker,
you will need Docker and Docker Compose (https://www.docker.com/get-started)

The docker-compose.yml file has been created to house the various services
that will be used. Feel free to comment out the services not needed by your
application.

- app <- the containers for the rails application
- webpacker
- sidekiq
- redis
- postgres

To get started, type "docker-compose up"
When finished, type "docker-compose down"
If you need to run migrations, you can run "docker-compose run app rails db:migrate"
You can also get into the rails console with "docker-compose run app rails console"
EOF