how to set the service mode when using docker compose?

Question

I need to set service mode to global while using compose files .

Any chance we can use this in compose file ? I have a requirement where for a service there should be exactly one container on every node/host .

This doesn't happen with "spread strategy" of swarm if a node goes down & comes up , it just attains the equal number of containers on each host irrespective of services .

https://github.com/docker/compose/issues/3743

Answer 1

We can do this easily now with docker compose v3 (version 3) under the deploy(mode) section.

Prerequisites -

docker compose version should be 1.10.0+

docker engine version should be 1.13.0+

Example compose file -

version: "3"

  services:
    nginx:
      image: nexus3.example.com/prd-nginx-sm:v1
      ports:
        - "80:80"
      networks:
        - cheers
      volumes:
        - logs:/rest/out/
      deploy:
        mode: global
        labels:
          feature.description: "Frontend"
        update_config:
          parallelism: 1
          delay: 10s
        restart_policy:
          condition: any
      command: "/usr/sbin/nginx"

networks:
  cheers:

volumes:
  logs:
  data:

Deploy the compose file -

$ docker stack deploy -c sm-deploy-compose.yml --with-registry-auth CHEERS

This will deploy nginx container on all the nodes participating in the cluster .