Cluster and app management services in Docker Cloud are shutting down on May 21
We are extremely worried about the future of Docker Swarm as well. 
We love Swarm - but we are seeing most work out of the Docker team is to give  a migration path to kubernetes. A huge number of docker swarm networking bugs are not being worked on.We will be happy if Docker talks about Swarm becoming a management UX for K8s - but we need visibility. These are production orchestration systems. The migration path is not easy.And seeing what Docker Co is doing with Cloud, it is not very comforting to trust that they will do the right thing with Swarm.