Docker swarm get deployment status

After running docker stack deploy to deploy some services to swarm is there a way to programmatically test if all containers started correctly?

The purpose would be to verify in a staging CI/CD pipeline that the containers are actually running and didn't fail on startup. Restart is disabled via restart_policy.

I was looking at docker stack services, is the replicas column useful for this purpose?

$ docker stack services --format "{{.ID}} {{.Replicas}}" my-stack-name
lxoksqmag0qb 0/1
ovqqnya8ato4 0/1

Typically in CI/CD I see everyone using docker or docker-compose. A container runs the same in docker as it does docker swarm with respects to "does this container work by itself as intended".

That being said, if you still wanted to do integration testing in a multi-tier solution with swarm, you could do various things in automation. Note this would all be done on a single node swarm to make testing easier (docker events doesn't pull node events from all nodes, so tracking a single node is much easier for ci/cd):

1. Have something monitoring docker events, e.g. docker events -f service=<service-name> to ensure containers aren't dying.
2. always have healthchecks in your containers. They are the #1 way to ensure your app is healthy (at the container level) and you'll see them succeed or fail in docker events. You can put them in Dockerfiles, service create commands, and stack/compose files. Here's some great examples.
3. You could attach another container to the same network to test your services remotely 1-by-1 using tasks. with reverse DNS. This will avoid the VIP and let you talk to a specific replica(s).
4. You might get some stuff out of docker inspect <service-id or task-id>