I think most people would suggest that, if your use case is at a stage where that is important to you, Swarm is not the right thing. Kubernetes or ECS are better choices.
I wouldn't recommend ECS. I've used it for a little over 6 months and even for trivial things, it lacks. A couple examples that come to mind include not being able to pass host environment variables into your container instances easily, and not being able to specify that a service must run on all hosts.
Theres an open issue (made ~2 years ago) on GH for the 1st example and it still hasn't been resolved.
Theres an open issue (made ~2 years ago) on GH for the 1st example and it still hasn't been resolved.