role

The name or full Amazon Resource Name (ARN) of the IAM role that allows Amazon ECS to make calls to your load balancer on your behalf. This parameter is only permitted if you are using a load balancer with your service and your task definition doesn't use the awsvpc network mode. If you specify the role parameter, you must also specify a load balancer object with the loadBalancers parameter.

If your account has already created the Amazon ECS service-linked role, that role is used for your service unless you specify a role here. The service-linked role is required if your task definition uses the awsvpc network mode or if the service is configured to use service discovery, an external deployment controller, multiple target groups, or Elastic Inference accelerators in which case you don't specify a role here. For more information, see Using service-linked roles for Amazon ECS in the Amazon Elastic Container Service Developer Guide.

If your specified role has a path other than /, then you must either specify the full role ARN (this is recommended) or prefix the role name with the path. For example, if a role with the name bar has a path of /foo/ then you would specify /foo/bar as the role name. For more information, see Friendly names and paths in the IAM User Guide.