# ecs-service — ECS Fargate service (task definition + service)

> **Module kind:** primitive  |  **Version:** 1.0.0

An ECS Fargate service with its task definition. Runs a container image
on Fargate, optionally behind an ALB target group. This is a
multi-resource module: it creates a task definition and a service that
runs it.

## Resources

| Resource | Type | Purpose |
|----------|------|---------|
| task_definition | `aws_ecs_task_definition` | Fargate task definition with container image, CPU, memory, port, env |
| service | `aws_ecs_service` | Fargate service running the task definition in a cluster + subnets |

## Inputs

| Name | Type | Required | Default | Description |
|------|------|----------|---------|-------------|
| `image` | string | yes | — | ECR image URL for the task container |
| `port` | number | yes | — | Container port the service listens on |
| `cpu` | number | no | 256 | Task CPU units (Fargate) |
| `memory` | number | no | 512 | Task memory in MiB (Fargate) |
| `env` | string | no | — | Environment variables as a JSON map string |
| `cluster_arn` | arn | yes | — | ECS cluster ARN (from `ecs-cluster`) |
| `subnets` | string | yes | — | Comma-separated subnet ids (from `vpc`) |
| `security_group` | string | yes | — | Security group id for the service ENIs |
| `lb_target_group_arn` | arn | no | — | Optional ALB target group ARN (from `alb`) |
| `region` | string | yes | — | AWS region the service is created in |

## Outputs

| Name | Type | Description |
|------|------|-------------|
| `service_arn` | arn | The ECS service ARN |
| `task_def_arn` | arn | The ECS task definition ARN |

## Usage

```json
{
  "id": "service",
  "type": "aws:ecs:task_definition",
  "module": "ecs-service@1.0.0",
  "inputs": {
    "image": "581513795199.dkr.ecr.us-east-1.amazonaws.com/acdl-microservice:latest",
    "port": 8080,
    "cpu": 256,
    "memory": 512,
    "cluster_arn": "ref:cluster.cluster_arn",
    "subnets": "ref:vpc.subnet_ids",
    "security_group": "ref:roles.role_arn",
    "region": "us-east-1"
  }
}
```

The `image`, `port`, and `env` inputs are compiled into a
`container_definitions` JSON block by the adapter. The service is
placed in the cluster with the given subnets and security group, and
optionally wired to the ALB target group if `lb_target_group_arn` is
provided.

## Compliance extension points

- **CloudWatch Logs** — add `logConfiguration` to the container definition with a log group + retention policy (SOX, SOC2 CC7.2, HIPAA §164.312(b), DORA ICT incident logging).
- **Task execution role separation** — add a separate `aws_iam_role` for execution vs. the task role (SOC2 CC6.3 segregation of duties at runtime).
- **Secrets injection** — add `secrets` block referencing AWS Secrets Manager / SSM Parameter Store with KMS encryption (SOC2 CC6.1, HIPAA §164.312(a)(2)(iv)).
- **Execute command** — add `enable_execute_command` with KMS encryption for session audit (SOC2 CC7.2).
- **Deployment circuit breaker** — add `deployment_circuit_breaker` block for resilience (SOC2 CC9.1, DORA operational resilience).
- **Health check** — add a `health_check` block to the target group (currently missing despite the contract schema having a healthcheck field).

## Versioning

`1.0.0` — interface MAJOR, behavior MINOR, lifecycle PATCH. MAJOR bumps
require a new registry entry (immutable publication); old entries enter
a 12-month deprecation window.