Run CLI command on ECS Fargate container

Question

How is it possible to run a CLI command within a container that's using ECS/Fargate?

Answer 1

DEPRECATED: As mentioned on this answer (How can I run commands in a running container in AWS ECS using Fargate) you cannot do it due to the fact AWS doesn't give you access to the underlying infrastructure.

UPDATE: Pierre below mentions an announcement from AWS allowing to do just that.