AWS::ECS::Cluster

• Container runtime service
• Container applications run in the OS just as a process
• With ECS you must provision and maintain the underlying EC2 instances
• ECS is basically a scheduler! To decide to which instance the container will be provisioned

• A ECS Cluster is a collection of ECS Container Instances
• The services run in the ECS cluster. Each service is compose of one or more tasks
• Services can be exposed by a Load Balancer

• Container: Container
• Task: Pod
• Service: Deployment
• Cluster: Cluster

Scaling

• A CloudWatch alarm can be set in order to emit events based on the service metrics
• Autoscaling can be enabled based on the metrics
• For EC2 Launch Type, Scale ECS Capacity Providers to scale the ec2 instances

Properties

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-cluster.html

Type: AWS::ECS::Cluster
Properties:
  CapacityProviders:
    - String
  ClusterName: String
  ClusterSettings:
    - ClusterSettings
  Configuration:
    ClusterConfiguration
  DefaultCapacityProviderStrategy:
    - CapacityProviderStrategyItem
  ServiceConnectDefaults:
    ServiceConnectDefaults
  Tags:
    - Tag

CapacityProviders

• EC2 Launch Type

• An ECS Agent runs inside each EC2 instances

• This agent registers the instance to the ECS Cluster
• Registered instances can receive ECS Tasks, which are container workloads
• Charged based on EC2 instances and EBS volumes

• In order to forward requests to the applications, dynamic port mapping is used

• Fargate Launch Type

• No need the provision the underlying infrastructure. Simpler! Serverless!

• Each ECS Task is associated with a new ENI in the EC2 Cluster (needs a long range VPC)

• Charged based on vCPU and memory resources

• For forwarding traffic, the Load Balancer forwards to each IP (each task has a unique ENI)