# Ecs

> AWS ECS container orchestration for running Docker containers. Use when deploying containerized applications, configuring task definitions, setting up services, managing clusters, or troubleshooting container issues.

- **Type:** Skill
- **Install:** `agentstack add skill-itsmostafa-aws-agent-skills-ecs`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [itsmostafa](https://agentstack.voostack.com/s/itsmostafa)
- **Installs:** 0
- **Category:** [Cloud & Infrastructure](https://agentstack.voostack.com/c/cloud-infrastructure)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [itsmostafa](https://github.com/itsmostafa)
- **Source:** https://github.com/itsmostafa/aws-agent-skills/tree/main/skills/ecs

## Install

```sh
agentstack add skill-itsmostafa-aws-agent-skills-ecs
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# AWS ECS

Amazon Elastic Container Service (ECS) is a fully managed container orchestration service. Run containers on AWS Fargate (serverless) or EC2 instances.

## Table of Contents

- [Core Concepts](#core-concepts)
- [Common Patterns](#common-patterns)
- [CLI Reference](#cli-reference)
- [Best Practices](#best-practices)
- [Troubleshooting](#troubleshooting)
- [References](#references)

## Core Concepts

### Cluster

Logical grouping of tasks or services. Can contain Fargate tasks, EC2 instances, or both.

### Task Definition

Blueprint for your application. Defines containers, resources, networking, and IAM roles.

### Task

Running instance of a task definition. Can run standalone or as part of a service.

### Service

Maintains desired count of tasks. Handles deployments, load balancing, and auto scaling.

### Launch Types

| Type | Description | Use Case |
|------|-------------|----------|
| **Fargate** | Serverless, pay per task | Most workloads |
| **EC2** | Self-managed instances | GPU, Windows, specific requirements |

## Common Patterns

### Create a Fargate Cluster

**AWS CLI:**

```bash
# Create cluster
aws ecs create-cluster --cluster-name my-cluster

# With capacity providers
aws ecs create-cluster \
  --cluster-name my-cluster \
  --capacity-providers FARGATE FARGATE_SPOT \
  --default-capacity-provider-strategy \
    capacityProvider=FARGATE,weight=1 \
    capacityProvider=FARGATE_SPOT,weight=1
```

### Register Task Definition

```bash
cat > task-definition.json  100
aws cloudwatch put-metric-alarm \
  --alarm-name queue-scale-out \
  --metric-name ApproximateNumberOfMessagesVisible \
  --namespace AWS/SQS \
  --dimensions Name=QueueName,Value=my-queue \
  --statistic Average \
  --period 60 \
  --evaluation-periods 1 \
  --threshold 100 \
  --comparison-operator GreaterThanThreshold \
  --alarm-actions 

# Scale-in alarm: queue empty for 3 periods (conservative to avoid flapping)
aws cloudwatch put-metric-alarm \
  --alarm-name queue-scale-in \
  --metric-name ApproximateNumberOfMessagesVisible \
  --namespace AWS/SQS \
  --dimensions Name=QueueName,Value=my-queue \
  --statistic Average \
  --period 60 \
  --evaluation-periods 3 \
  --threshold 0 \
  --comparison-operator LessThanOrEqualToThreshold \
  --alarm-actions 
```

**Fargate Spot interruption handling:** Spot tasks receive a SIGTERM 2 minutes before termination. Catch it in your application for graceful shutdown. For SQS consumers, call `ChangeMessageVisibility` on in-flight messages so they return to the queue rather than timing out.

### Auto Scaling

```bash
# Register scalable target
aws application-autoscaling register-scalable-target \
  --service-namespace ecs \
  --resource-id service/my-cluster/web-service \
  --scalable-dimension ecs:service:DesiredCount \
  --min-capacity 2 \
  --max-capacity 10

# Target tracking policy
aws application-autoscaling put-scaling-policy \
  --service-namespace ecs \
  --resource-id service/my-cluster/web-service \
  --scalable-dimension ecs:service:DesiredCount \
  --policy-name cpu-target-tracking \
  --policy-type TargetTrackingScaling \
  --target-tracking-scaling-policy-configuration '{
    "TargetValue": 70.0,
    "PredefinedMetricSpecification": {
      "PredefinedMetricType": "ECSServiceAverageCPUUtilization"
    },
    "ScaleOutCooldown": 60,
    "ScaleInCooldown": 120
  }'
```

## CLI Reference

### Cluster Management

| Command | Description |
|---------|-------------|
| `aws ecs create-cluster` | Create cluster |
| `aws ecs describe-clusters` | Get cluster details |
| `aws ecs list-clusters` | List clusters |
| `aws ecs delete-cluster` | Delete cluster |

### Task Definitions

| Command | Description |
|---------|-------------|
| `aws ecs register-task-definition` | Create task definition |
| `aws ecs describe-task-definition` | Get task definition |
| `aws ecs list-task-definitions` | List task definitions |
| `aws ecs deregister-task-definition` | Deregister version |

### Services

| Command | Description |
|---------|-------------|
| `aws ecs create-service` | Create service |
| `aws ecs update-service` | Update service |
| `aws ecs describe-services` | Get service details |
| `aws ecs delete-service` | Delete service |

### Tasks

| Command | Description |
|---------|-------------|
| `aws ecs run-task` | Run standalone task |
| `aws ecs stop-task` | Stop running task |
| `aws ecs describe-tasks` | Get task details |
| `aws ecs list-tasks` | List tasks |

## Best Practices

### Security

- **Use task roles** for AWS API access (not access keys)
- **Use execution roles** for ECR/Secrets access
- **Store secrets in Secrets Manager** or Parameter Store
- **Use private subnets** with NAT gateway
- **Enable CloudTrail** for API auditing

### Performance

- **Right-size CPU/memory** — monitor and adjust
- **Use Fargate Spot** for fault-tolerant workloads (70% savings)
- **Enable container insights** for monitoring
- **Use service discovery** for internal communication

### Reliability

- **Deploy across multiple AZs**
- **Configure health checks** properly
- **Set appropriate deregistration delay**
- **Use circuit breaker** for deployments

```bash
aws ecs update-service \
  --cluster my-cluster \
  --service web-service \
  --deployment-configuration '{
    "deploymentCircuitBreaker": {
      "enable": true,
      "rollback": true
    }
  }'
```

### Cost Optimization

- **Use Fargate Spot** for batch workloads
- **Right-size task resources**
- **Scale to zero** when not needed
- **Use capacity providers** for mixed Fargate/Spot

## Troubleshooting

### Task Fails to Start

**Check:**

```bash
# View stopped tasks
aws ecs describe-tasks \
  --cluster my-cluster \
  --tasks $(aws ecs list-tasks --cluster my-cluster --desired-status STOPPED --query 'taskArns[0]' --output text)
```

**Common causes:**
- Image not found (ECR permissions)
- Secrets access denied
- Network configuration (subnets, security groups)
- Resource limits exceeded

### Container Keeps Restarting

**Debug:**

```bash
# Check CloudWatch logs
aws logs get-log-events \
  --log-group-name /ecs/web-app \
  --log-stream-name "ecs/web/abc123"

# Check task details
aws ecs describe-tasks \
  --cluster my-cluster \
  --tasks task-arn \
  --query 'tasks[0].containers[0].{reason:reason,exitCode:exitCode}'
```

**Causes:**
- Health check failing
- Application crashing
- Out of memory

### Live Debugging with ECS Exec

Connect directly to a running container without SSH. Requires `enableExecuteCommand: true` on the service and the SSM agent in your container image (included in most base images).

```bash
# Enable on existing service
aws ecs update-service \
  --cluster my-cluster \
  --service web-service \
  --enable-execute-command

# Get a shell in a running task
TASK_ARN=$(aws ecs list-tasks --cluster my-cluster --service-name web-service \
  --query 'taskArns[0]' --output text)

aws ecs execute-command \
  --cluster my-cluster \
  --task $TASK_ARN \
  --container web \
  --interactive \
  --command "/bin/sh"
```

**Requirements:** Task role must have `ssmmessages:CreateControlChannel`, `ssmmessages:CreateDataChannel`, `ssmmessages:OpenControlChannel`, `ssmmessages:OpenDataChannel` permissions.

### Service Stuck Deploying

```bash
# Check deployment status
aws ecs describe-services \
  --cluster my-cluster \
  --services web-service \
  --query 'services[0].deployments'

# Check events
aws ecs describe-services \
  --cluster my-cluster \
  --services web-service \
  --query 'services[0].events[:5]'
```

**Causes:**
- Health check failing on new tasks
- Not enough capacity
- Target group health checks failing

### Cannot Pull Image from ECR

**Check execution role has:**

```json
{
  "Effect": "Allow",
  "Action": [
    "ecr:GetAuthorizationToken",
    "ecr:BatchCheckLayerAvailability",
    "ecr:GetDownloadUrlForLayer",
    "ecr:BatchGetImage"
  ],
  "Resource": "*"
}
```

**Also check:**
- VPC endpoint for ECR (if private subnet)
- NAT gateway (if private subnet)
- Security group allows HTTPS outbound

## References

- [ECS Developer Guide](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/)
- [ECS API Reference](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/)
- [ECS CLI Reference](https://docs.aws.amazon.com/cli/latest/reference/ecs/)
- [boto3 ECS](https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html)

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [itsmostafa](https://github.com/itsmostafa)
- **Source:** [itsmostafa/aws-agent-skills](https://github.com/itsmostafa/aws-agent-skills)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** yes
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-itsmostafa-aws-agent-skills-ecs
- Seller: https://agentstack.voostack.com/s/itsmostafa
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.