Where "tasks" subcommand has gone?

I used a couple of weeks ago “docker service tasks” for accessing information about where containers related to a service where running. I can’t remember clearly but it worked quite similar to “docker-compose ps” because I could see container’s ids and swarm nodes, and can access them using the full name or id (with their node). But when trying to create services again, after updating from 1.12RC2 to 1.12 I don’t have “docker service tasks”. Am I wrong?, Did I have dreamed that options?
How can I attach or read a log now?, Do I have to go to a node with that container? I can’t “docker run” when using swarm mode, so I can’t attach a debuging container to a swarm created network (interactive mode)?
Many Thanks for Your Help,
Javier R.

I missed that my current docker version is 1.12.1.
Many Thanks,
Javier R.