Stacks

Question 1

What is a stack?

Answer 1

A stack is a group of interrelated services that share dependencies, and can be orchestrated and scaled together.

Question 2

Give an example of how to persist data between deployment of the stacks

Answer 2

ex.
redis:
    image: redis
    ports:
      - "6379:6739"
    volumes:
      - ./data:/data
    deploy:
      placement:
        constraints: [node.role == manager]
    networks:
      - webnet

• redis always runs on the manager, so it’s always using the same filesystem.
• redis accesses an arbitrary directory in the host’s file system as /data inside the container, which is where Redis stores data. (The volume you created that lets the container access ./data (on the host) as /data (inside the Redis container). While containers come and go, the files stored on ./data on the specified host will persist, enabling continuity.)