Not GP, but I recently attempted to migrate a single-node Docker Compose setup to Docker Swarm and ran into the following issues:
- No ability to use secrets as environment variables, and no plans to change this
- Cannot use `network_mode` to specify a service to use for network connections a la Docker Compose
There were a few other minor issues which resulted in ditching Docker Swarm completely and moving to a Nomad + Consul stack instead.