Exemplo de docker compose para rails + sidekiq + redis + banco de dados

docker-compose.yml

version: "2"

services:
  app:
    build:
      context: .
    container_name: my_container
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
    volumes:
      - .:/usr/src/app
      - my_bundle:/usr/local/bundle
    ports:
      - 3000:3000
    stdin_open: true
    tty: true
    env_file:
      - ${ENV_FILE:-.env}
    depends_on:
      - db

  db:
    image: postgres
    container_name: my_db
    volumes:
      - pg_data:/var/lib/postgresql/data
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    ports:
      - "5432:5432"

  sidekiq:
    image: my_app # aqui é o nome da imagem que é gerado do serviço app
    container_name: my_sidekiq
    tty: true
    stdin_open: true
    depends_on:
      - app
      - db
      - redis
    volumes:
      - .:/app
      - my_bundle:/usr/local/bundle
    command: bundle exec sidekiq -C config/sidekiq.yml
    
  redis:
    image: redis:7.0.10-alpine
    container_name: my_redis
    command: redis-server
    volumes:
      - redis_data:/data
    ports:
      - "6379:6379"
    logging:
      driver: none

  mailcatcher:
    restart: on-failure
    image: dockage/mailcatcher:0.8.2
    ports:
      - "1080:1080"
      - "1025:1025"

volumes:
  pg_data:
  my_bundle:
  redis_data:

Dockerfile

FROM ruby:3.1.2

ARG NODE_MAJOR_VERSION=20
RUN curl -sL https://deb.nodesource.com/setup_$NODE_MAJOR_VERSION.x | bash -
RUN apt-get update -qq && \
    apt-get install -y build-essential libvips nodejs libpq-dev postgresql-client && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/* /usr/share/doc /usr/share/man && \
    npm install -g yarn

RUN mkdir /usr/src/app
WORKDIR /usr/src/app
ADD . /usr/src/app
RUN gem install bundler -v 2.3.26
RUN bundle install