rails tutorial dockerfile

docker-compose.yml

version: '2'
services:
  app:
    build: .
    environment:
      - "DATABASE_HOST=db"
      - "DATABASE_PORT=5432"
      - "DATABASE_USER=postgres"
      - "DATABASE_PASSWORD=password"
    ports:
      - '3000:3000'
    volumes:
      - .:/app
    links:
      - db
  db:
    image: postgres:10.1
    ports:
      - "5432:5432"
    environment:
      - "POSTGRES_USER=postgres"
      - "POSTGRES_PASSWORD=password"

Dockerfile

FROM ruby:2.5.1

WORKDIR /app

COPY Gemfile* /app/

RUN apt-get update && \
  apt-get install -y nodejs \
  mysql-client \
  postgresql-client \
  sqlite3 \
  --no-install-recommends

RUN bundle config --global frozen 1 \
  && bundle install -j4 --retry 3 \
  && rm -rf /usr/local/bundle/cache/*.gem \
  && find /usr/local/bundle/gems/ -name "*.c" -delete \
  && find /usr/local/bundle/gems/ -name "*.o" -delete
COPY . /app
EXPOSE  3000
CMD ["rails", "server", "-b", "0.0.0.0"]