loadBalancers

A load balancer object representing the load balancers to use with your service. For more information, see Service load balancing in the Amazon Elastic Container Service Developer Guide.

If the service uses the rolling update (ECS) deployment controller and using either an Application Load Balancer or Network Load Balancer, you must specify one or more target group ARNs to attach to the service. The service-linked role is required for services that use multiple target groups. For more information, see Using service-linked roles for Amazon ECS in the Amazon Elastic Container Service Developer Guide.

If the service uses the CODE_DEPLOY deployment controller, the service is required to use either an Application Load Balancer or Network Load Balancer. When creating an CodeDeploy deployment group, you specify two target groups (referred to as a targetGroupPair). During a deployment, CodeDeploy determines which task set in your service has the status PRIMARY, and it associates one target group with it. Then, it also associates the other target group with the replacement task set. The load balancer can also have up to two listeners: a required listener for production traffic and an optional listener that you can use to perform validation tests with Lambda functions before routing production traffic to it.

If you use the CODE_DEPLOY deployment controller, these values can be changed when updating the service.

For Application Load Balancers and Network Load Balancers, this object must contain the load balancer target group ARN, the container name, and the container port to access from the load balancer. The container name must be as it appears in a container definition. The load balancer name parameter must be omitted. When a task from this service is placed on a container instance, the container instance and port combination is registered as a target in the target group that's specified here.

For Classic Load Balancers, this object must contain the load balancer name, the container name , and the container port to access from the load balancer. The container name must be as it appears in a container definition. The target group ARN parameter must be omitted. When a task from this service is placed on a container instance, the container instance is registered with the load balancer that's specified here.

Services with tasks that use the awsvpc network mode (for example, those with the Fargate launch type) only support Application Load Balancers and Network Load Balancers. Classic Load Balancers aren't supported. Also, when you create any target groups for these services, you must choose ip as the target type, not instance. This is because tasks that use the awsvpc network mode are associated with an elastic network interface, not an Amazon EC2 instance.