targetGroupArn

The full Amazon Resource Name (ARN) of the Elastic Load Balancing target group or groups associated with a service or task set.

A target group ARN is only specified when using an Application Load Balancer or Network Load Balancer.

For services using the ECS deployment controller, you can specify one or multiple target groups. For more information, see Registering multiple target groups with a service in the Amazon Elastic Container Service Developer Guide.

For services using the CODE_DEPLOY deployment controller, you're required to define two target groups for the load balancer. For more information, see Blue/green deployment with CodeDeploy in the Amazon Elastic Container Service Developer Guide.

If your service's task definition uses the awsvpc network mode, you must choose ip as the target type, not instance. Do this when creating your target groups because tasks that use the awsvpc network mode are associated with an elastic network interface, not an Amazon EC2 instance. This network mode is required for the Fargate launch type.