Cloudformation Agent Skill

AWS CloudFormation infrastructure as code for stack management. Use when writing templates, deploying stacks, managing drift, troubleshooting deployments, or organizing infrastructure with nested stacks.

5k tokens

context cost

the whole folder, loaded on every use

files

instructions only

copies elsewhere

how many repositories repackaged it

1139

stars on the repo

on the repository, not the skill itself

Install

one command, takes just this skill from the repository

npx skills add https://github.com/itsmostafa/aws-agent-skills --skill cloudformation

The instruction itself

29 sections, as written by the author

AWS CloudFormation

AWS CloudFormation provisions and manages AWS resources using templates. Define infrastructure as code, version control it, and deploy consistently across environments.

Core Concepts
Common Patterns
CLI Reference
Best Practices
Troubleshooting
References

Core Concepts

Templates

JSON or YAML files defining AWS resources. Key sections:

Parameters: Input values
Mappings: Static lookup tables
Conditions: Conditional resource creation
Resources: AWS resources (required)
Outputs: Return values

Stacks

Collection of resources managed as a single unit. Created from templates.

Change Sets

Preview changes before executing updates.

Stack Sets

Deploy stacks across multiple accounts and regions.

Common Patterns

Basic Template Structure

AWSTemplateFormatVersion: '2010-09-09'
Description: My infrastructure template

Parameters:
  Environment:
    Type: String
    AllowedValues: [dev, staging, prod]
    Default: dev

Mappings:
  EnvironmentConfig:
    dev:
      InstanceType: t3.micro
    prod:
      InstanceType: t3.large

Conditions:
  IsProd: !Equals [!Ref Environment, prod]

Resources:
  MyBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Sub 'my-app-${Environment}-${AWS::AccountId}'
      VersioningConfiguration:
        Status: !If [IsProd, Enabled, Suspended]

Outputs:
  BucketName:
    Description: S3 bucket name
    Value: !Ref MyBucket
    Export:
      Name: !Sub '${AWS::StackName}-BucketName'

Deploy a Stack

AWS CLI:

# Create stack
aws cloudformation create-stack \
  --stack-name my-stack \
  --template-body file://template.yaml \
  --parameters ParameterKey=Environment,ParameterValue=prod \
  --capabilities CAPABILITY_IAM

# Wait for completion
aws cloudformation wait stack-create-complete --stack-name my-stack

# Update stack
aws cloudformation update-stack \
  --stack-name my-stack \
  --template-body file://template.yaml \
  --parameters ParameterKey=Environment,ParameterValue=prod

# Delete stack
aws cloudformation delete-stack --stack-name my-stack

Use Change Sets

# Create change set
aws cloudformation create-change-set \
  --stack-name my-stack \
  --change-set-name my-changes \
  --template-body file://template.yaml \
  --parameters ParameterKey=Environment,ParameterValue=prod

# Describe changes
aws cloudformation describe-change-set \
  --stack-name my-stack \
  --change-set-name my-changes

# Execute change set
aws cloudformation execute-change-set \
  --stack-name my-stack \
  --change-set-name my-changes

Lambda Function

Resources:
  LambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      FunctionName: !Sub '${AWS::StackName}-function'
      Runtime: python3.12
      Handler: index.handler
      Role: !GetAtt LambdaRole.Arn
      Code:
        ZipFile: |
          def handler(event, context):
              return {'statusCode': 200, 'body': 'Hello'}
      Environment:
        Variables:
          ENVIRONMENT: !Ref Environment

  LambdaRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: sts:AssumeRole
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

VPC with Subnets

Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsHostnames: true
      Tags:
        - Key: Name
          Value: !Sub '${AWS::StackName}-vpc'

  PublicSubnet1:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      AvailabilityZone: !Select [0, !GetAZs '']
      CidrBlock: 10.0.1.0/24
      MapPublicIpOnLaunch: true

  PrivateSubnet1:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      AvailabilityZone: !Select [0, !GetAZs '']
      CidrBlock: 10.0.10.0/24

  InternetGateway:
    Type: AWS::EC2::InternetGateway

  AttachGateway:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref InternetGateway

  PublicRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC

  PublicRoute:
    Type: AWS::EC2::Route
    DependsOn: AttachGateway
    Properties:
      RouteTableId: !Ref PublicRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref InternetGateway

  PublicSubnet1RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet1
      RouteTableId: !Ref PublicRouteTable

DynamoDB Table

Resources:
  OrdersTable:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: !Sub '${AWS::StackName}-orders'
      AttributeDefinitions:
        - AttributeName: PK
          AttributeType: S
        - AttributeName: SK
          AttributeType: S
        - AttributeName: GSI1PK
          AttributeType: S
        - AttributeName: GSI1SK
          AttributeType: S
      KeySchema:
        - AttributeName: PK
          KeyType: HASH
        - AttributeName: SK
          KeyType: RANGE
      GlobalSecondaryIndexes:
        - IndexName: GSI1
          KeySchema:
            - AttributeName: GSI1PK
              KeyType: HASH
            - AttributeName: GSI1SK
              KeyType: RANGE
          Projection:
            ProjectionType: ALL
      BillingMode: PAY_PER_REQUEST
      PointInTimeRecoverySpecification:
        PointInTimeRecoveryEnabled: true

CLI Reference

Stack Operations

| Command | Description |

|---------|-------------|

| aws cloudformation create-stack | Create stack |

| aws cloudformation update-stack | Update stack |

| aws cloudformation delete-stack | Delete stack |

| aws cloudformation describe-stacks | Get stack info |

| aws cloudformation list-stacks | List stacks |

| aws cloudformation describe-stack-events | Get events |

| aws cloudformation describe-stack-resources | Get resources |

Change Sets

| Command | Description |

|---------|-------------|

| aws cloudformation create-change-set | Create change set |

| aws cloudformation describe-change-set | View changes |

| aws cloudformation execute-change-set | Apply changes |

| aws cloudformation delete-change-set | Delete change set |

Template

| Command | Description |

|---------|-------------|

| aws cloudformation validate-template | Validate template |

| aws cloudformation get-template | Get stack template |

| aws cloudformation get-template-summary | Get template info |

Best Practices

Template Design

Use parameters for environment-specific values
Use mappings for static lookup tables
Use conditions for optional resources
Export outputs for cross-stack references
Add descriptions to parameters and outputs

Security

Use IAM roles instead of access keys
Enable termination protection for production
Use stack policies to protect resources
Never hardcode secrets — use Secrets Manager

# Enable termination protection
aws cloudformation update-termination-protection \
  --stack-name my-stack \
  --enable-termination-protection

Organization

Use nested stacks for complex infrastructure
Create reusable modules
Version control templates
Use consistent naming conventions

Reliability

Use DependsOn for explicit dependencies
Configure creation policies for instances
Use update policies for Auto Scaling groups
Implement rollback triggers

Troubleshooting

Stack Creation Failed

# Get failure reason
aws cloudformation describe-stack-events \
  --stack-name my-stack \
  --query 'StackEvents[?ResourceStatus==`CREATE_FAILED`]'

# Common causes:
# - IAM permissions
# - Resource limits
# - Invalid property values
# - Dependency failures

Stack Stuck in DELETE_FAILED

# Identify resources that couldn't be deleted
aws cloudformation describe-stack-resources \
  --stack-name my-stack \
  --query 'StackResources[?ResourceStatus==`DELETE_FAILED`]'

# Retry with resources to skip
aws cloudformation delete-stack \
  --stack-name my-stack \
  --retain-resources ResourceLogicalId1 ResourceLogicalId2

Drift Detection

# Detect drift
aws cloudformation detect-stack-drift --stack-name my-stack

# Check drift status
aws cloudformation describe-stack-drift-detection-status \
  --stack-drift-detection-id abc123

# View drifted resources
aws cloudformation describe-stack-resource-drifts \
  --stack-name my-stack

Rollback Failed

# Continue update rollback
aws cloudformation continue-update-rollback \
  --stack-name my-stack \
  --resources-to-skip ResourceLogicalId1

References

Other skills for the same job

different authors, same section of the catalogue

Azure Kubernetes Automatic Readiness

by microsoft

vendor ×3

Assess Kubernetes workloads and cluster configuration for AKS Automatic compatibility. Identifies incompatibilities, generates fixes, and guides migration from AKS Standard to AKS Automatic. WHEN: migrate to AKS Automatic, check AKS Automatic readiness, validate manifests for Automatic, assess cluster for Automatic compatibility, fix deployment for Automatic compatibility, identify AKS Automatic migration blockers, is my cluster ready for AKS Automatic.

Discovers available Azure OpenAI model capacity across regions and projects. Analyzes quota limits, compares availability, and recommends optimal deployment locations based on capacity requirements. USE FOR: find capacity, check quota, where can I deploy, capacity discovery, best region for capacity, multi-project capacity search, quota analysis, model availability, region comparison, check TPM availability. DO NOT USE FOR: actual deployment (hand off to preset or customize after discovery), quota increase requests (direct user to Azure Portal), listing existing deployments.

Interactive guided deployment flow for Azure OpenAI models with full customization control. Step-by-step selection of model version, SKU (GlobalStandard/Standard/ProvisionedManaged), capacity, RAI policy (content filter), and advanced options (dynamic quota, priority processing, spillover). USE FOR: custom deployment, customize model deployment, choose version, select SKU, set capacity, configure content filter, RAI policy, deployment options, detailed deployment, advanced deployment, PTU deployment, provisioned throughput. DO NOT USE FOR: quick deployment to optimal region (use preset).

Unified Azure OpenAI model deployment skill with intelligent intent-based routing. Handles quick preset deployments, fully customized deployments (version/SKU/capacity/RAI policy), and capacity discovery across regions and projects. USE FOR: deploy model, deploy gpt, create deployment, model deployment, deploy openai model, set up model, provision model, find capacity, check model availability, where can I deploy, best region for model, capacity analysis. DO NOT USE FOR: listing existing deployments (use foundry_models_deployments_list MCP tool), deleting deployments, agent creation (use agent/create), project creation (use project/create).

Intelligently deploys Azure OpenAI models to optimal regions by analyzing capacity across all available regions. Automatically checks current region first and shows alternatives if needed. USE FOR: quick deployment, optimal region, best region, automatic region selection, fast setup, multi-region capacity check, high availability deployment, deploy to best location. DO NOT USE FOR: custom SKU selection (use customize), specific version selection (use customize), custom capacity configuration (use customize), PTU deployments (use customize).

This skill should be used when working with LaminDB, an open-source data framework for biology that makes data queryable, traceable, reproducible, and FAIR. Use when managing biological datasets (scRNA-seq, spatial, flow cytometry, etc.), tracking computational workflows, curating and validating data with biological ontologies, building data lakehouses, or ensuring data lineage and reproducibility in biological research. Covers data management, annotation, ontologies (genes, cell types, diseases, tissues), schema validation, integrations with workflow managers (Nextflow, Snakemake) and MLOps platforms (W&B, MLflow), and deployment strategies.

Latch platform for bioinformatics workflows. Build pipelines with Latch SDK, @workflow/@task decorators, deploy serverless workflows, LatchFile/LatchDir, Nextflow/Snakemake integration.

Run Python code in the cloud with serverless containers, GPUs, and autoscaling. Use when deploying ML models, running batch processing jobs, scheduling compute-intensive tasks, or serving APIs that require GPU acceleration or dynamic scaling.

17k tokens

How to use it

Copy the folder

Take itsmostafa/cloudformation from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.

Cloudformation Agent Skill

Install

The instruction itself

AWS CloudFormation

Table of Contents

Core Concepts

Templates

Stacks

Change Sets

Stack Sets

Common Patterns

Basic Template Structure

Deploy a Stack

Use Change Sets

Lambda Function

VPC with Subnets

DynamoDB Table

CLI Reference

Stack Operations

Change Sets

Template

Best Practices

Template Design

Security

Organization

Reliability

Troubleshooting

Stack Creation Failed

Stack Stuck in DELETE_FAILED

Drift Detection

Rollback Failed

References

Other skills for the same job

How to use it