version: "3"
services:

  db:
    image: postgres:9.4
    volumes:
      - db-data:/var/lib/postgresql/data
    networks:
      - backend
    deploy:
      placement:
        constraints: [node.role == manager]

  sample_blog:
    image: quay.io/repository/copley/sample_blog
    ports:
      - 3000:80
    networks:
      - frontend
    deploy:
      replicas: 2
      update_config:
        parallelism: 2
      restart_policy:
        condition: on-failure

networks:
  frontend:
  backend:

volumes:
  db-data:

ID            NAME             MODE        REPLICAS  IMAGE
dingz17v0qor  sb_db            replicated  0/1       postgres:9.4
tq3lgqvwx627  sb_sample_blog   replicated  0/2       quay.io/repository/copley/sample_blog