Correct answer - ECS_ENABLE_TASK_IAM_ROLE : Enables IAM roles for tasks for
containers with the bridge and default network modes.
ECS_ENGINE_AUTH_DATA - The contents of a Docker configuration file
Elastic ECS_AVAILABLE_LOGGING_DRIVERS - The Amazon ECS container agent running on a
container instance must register the logging drivers available on that instance with this
variable
ECS_CLUSTER - Passed to the container instance at launch through Amazon EC2 user
data