Exec into docker cloud?
Yes, if you can open an ssh session on your docker cloud service (which is probably possible).
Or, more likely, if you run and access your container through a Docker Cloud Agent, which allows you to use any Linux host (“bring your own host”) as a node which you can then use to deploy containers.
Otherwise, no, as the socket used by docker cloud session would not be exposed through internet, and is used only locally on the remote cloud server.
You can use the approach here(https://docs.docker.com/docker-cloud/infrastructure/ssh-into-a-node/#ssh-into-docker-cloud-node) and it has worked for me.