Template Anatomy
- AWSTemplateFormatVersion, Description, Parameters, Mappings, Conditions, Resources (required), Outputs
- Intrinsic functions: !Ref, !GetAtt, !Sub, !Join, !Select, !If
- Pseudo parameters: AWS::Region, AWS::AccountId, AWS::StackName
- Max template size: 51,200 bytes (S3) or 460,800 bytes (body)
Stack Sets
- Deploy stacks across multiple accounts and regions
- Service-managed (Organizations) or self-managed permissions
- Deployment options: parallel/sequential, failure tolerance, max concurrency
- Auto-deployment: new accounts automatically get the stack
Drift Detection
- Detects changes made outside CloudFormation
- Resource-level and stack-level drift status
- IN_SYNC, MODIFIED, DELETED, NOT_CHECKED
- Cannot detect drift on all resource types
Advanced Features
- Custom resources: Lambda-backed for unsupported resources
- Change sets: preview updates before execution
- Nested stacks: reusable components, parent-child relationships
- DeletionPolicy: Retain, Snapshot, Delete
Practice CloudFormation Questions
Put your knowledge to the test with practice questions.