ECS Cluster Module

Deploy an AWS Elastic Container Service (ECS) cluster with EC2 or Fargate capacity providers.

What You'll Build

• ECS cluster with configurable capacity providers
• EC2 launch template for container hosts
• Auto Scaling Group for EC2 capacity
• CloudWatch Container Insights monitoring
• Optional ECS Service Autoscaling policies

How to Use

module "ecs_cluster" {
  source = "github.com/nnthanh101/terraform-aws/modules/ecs"

  name = "app-cluster"

  # EC2 capacity provider
  capacity_providers = ["EC2"]
  
  default_capacity_provider_strategy = {
    capacity_provider = "EC2"
    weight            = 100
    base              = 1
  }

  autoscaling_group_settings = {
    max_size         = 10
    min_size         = 2
    desired_capacity = 3
  }

  # Container Insights
  container_insights_enabled = true

  tags = {
    Environment = "prod"
    Service     = "platform"
  }
}

Key Variables

Variable	Type	Purpose
name	string	ECS cluster name
capacity_providers	list(string)	Capacity providers: "EC2" or "FARGATE"
default_capacity_provider_strategy	object	Default provider weight and base capacity
autoscaling_group_settings	object	ASG min/max/desired capacity
container_insights_enabled	bool	Enable CloudWatch Container Insights
instance_type	string	EC2 instance type for container hosts
on_demand_percentage	number	Percent on-demand vs spot (0-100)

Outputs

Output	Use Case
cluster_id	Cluster ID for task/service registration
cluster_arn	ARN for IAM policy references
cluster_name	Cluster name for CLI/API calls
autoscaling_group_id	ASG ID for scaling policy attachment

Integration

• ECS Tasks: Register task definitions and create services in the cluster
• CloudWatch: Container Insights provides metrics and logs
• Autoscaling: Attach Application Autoscaling policies to services
• Load Balancer: ALB target groups reference the ECS service
• IAM: Task execution role for pulling images and accessing secrets

Source Reference

Module: terraform-aws/modules/ecs