[Docker Compose + Traefik] Reverse proxying + customizing localhost domains using Traefik

docker-compose.yml

services:
  traefik:
    image: traefik:2.10
    command: --api.insecure=true --providers.docker
    ports:
      - "80:80"
      - "8080:8080"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
  rails1:
    build: .
    image: my-rails-app
    container_name: rails1
    labels:
      - "traefik.http.routers.rails1.rule=Host(`rails1.localhost`)" # access this app at rails1.localhost
    env_file: .env
    command: ['init_rails']
    volumes:
      - .:/app
      - ./scripts/docker/init_rails.sh:/bin/init_rails
    depends_on:
       - traefik
  rails2:
    build: .
    image: my-rails-app
    container_name: rails2
    labels:
      - "traefik.http.routers.rails2.rule=Host(`rails2.localhost`)" # access this app at rails2.localhost
    env_file: .env
    command: ['init_rails']
    volumes:
      - .:/app
      - ./scripts/docker/init_rails.sh:/bin/init_rails
    depends_on:
       - traefik