🧱 What is AWS CloudFormation?
AWS CloudFormation is an Infrastructure as Code (IaC) service that allows you to define and provision AWS resources using YAML or JSON templates.
✅ Think of it as a way to "script" your AWS setup — like EC2, S3, IAM, VPC, etc.
🧰 Key Features
| Feature | Description |
|---|---|
| IaC | Code your infrastructure like software (version-controlled, repeatable) |
| Templates | Define stacks in YAML or JSON |
| Stacks | A set of AWS resources created/updated/deleted together |
| Drift Detection | Detect manual changes outside CloudFormation |
| Change Sets | Preview changes before applying them |
| StackSets | Deploy stacks across multiple accounts and regions |
🧾 Sample YAML Template (Creates an EC2 Instance)
🔄 CloudFormation Workflow
🛠️ Ways to Deploy
- Console: Upload a file or write inline
-
AWS CLI:
aws cloudformation create-stack --template-body file://template.yaml - CI/CD: Integrate with CodePipeline or GitHub Actions
- SDKs: Automate via Python (Boto3), Java, etc.
🧠 Benefits
| Benefit | Why it Matters |
|---|---|
| Automation | Avoids manual AWS setup |
| Repeatability | Use same template to create environments |
| Auditability | Version control your infra like app code |
| Rollback | Automatically rolls back if deployment fails |
| Cross-account | Use StackSets for multi-account deployments |
❌ Limitations
- Steep learning curve for large templates
- Debugging complex stacks can be tricky
- YAML can get verbose for nested resources
✅ Ideal Use Cases
- Creating dev/test/prod environments consistently
- Managing multi-region architectures
- Setting up serverless apps (with AWS SAM or CDK)
- Deploying resources via CI/CD pipelines