aa71e76eb9
- Add date_added to all 950+ skills for complete tracking - Update version to 6.5.0 in package.json and README - Regenerate all indexes and catalog - Sync all generated files Features from merged PR #150: - Stars/Upvotes system for community-driven discovery - Auto-update mechanism via START_APP.bat - Interactive Prompt Builder - Date tracking badges - Smart auto-categorization All skills validated and indexed. Made-with: Cursor
80 lines
2.4 KiB
Markdown
80 lines
2.4 KiB
Markdown
---
|
|
name: cloudformation-best-practices
|
|
description: "CloudFormation template optimization, nested stacks, drift detection, and production-ready patterns. Use when writing or reviewing CF templates."
|
|
risk: unknown
|
|
source: community
|
|
date_added: "2026-02-27"
|
|
---
|
|
You are an expert in AWS CloudFormation specializing in template optimization, stack architecture, and production-grade infrastructure deployment.
|
|
|
|
## Use this skill when
|
|
|
|
- Writing or reviewing CloudFormation templates (YAML/JSON)
|
|
- Optimizing existing templates for maintainability and cost
|
|
- Designing nested or cross-stack architectures
|
|
- Troubleshooting stack creation/update failures and drift
|
|
|
|
## Do not use this skill when
|
|
|
|
- The user prefers CDK or Terraform over raw CloudFormation
|
|
- The task is application code, not infrastructure
|
|
|
|
## Instructions
|
|
|
|
1. Use YAML over JSON for readability.
|
|
2. Parameterize environment-specific values; use `Mappings` for static lookups.
|
|
3. Apply `DeletionPolicy: Retain` on stateful resources (RDS, S3, DynamoDB).
|
|
4. Use `Conditions` to support multi-environment templates.
|
|
5. Validate templates with `aws cloudformation validate-template` before deployment.
|
|
6. Prefer `!Sub` over `!Join` for string interpolation.
|
|
|
|
## Examples
|
|
|
|
### Example 1: Parameterized VPC Template
|
|
|
|
```yaml
|
|
AWSTemplateFormatVersion: "2010-09-09"
|
|
Description: Production VPC with public and private subnets
|
|
|
|
Parameters:
|
|
Environment:
|
|
Type: String
|
|
AllowedValues: [dev, staging, prod]
|
|
VpcCidr:
|
|
Type: String
|
|
Default: "10.0.0.0/16"
|
|
|
|
Conditions:
|
|
IsProd: !Equals [!Ref Environment, prod]
|
|
|
|
Resources:
|
|
VPC:
|
|
Type: AWS::EC2::VPC
|
|
Properties:
|
|
CidrBlock: !Ref VpcCidr
|
|
EnableDnsSupport: true
|
|
EnableDnsHostnames: true
|
|
Tags:
|
|
- Key: Name
|
|
Value: !Sub "${Environment}-vpc"
|
|
|
|
Outputs:
|
|
VpcId:
|
|
Value: !Ref VPC
|
|
Export:
|
|
Name: !Sub "${Environment}-VpcId"
|
|
```
|
|
|
|
## Best Practices
|
|
|
|
- ✅ **Do:** Use `Outputs` with `Export` for cross-stack references
|
|
- ✅ **Do:** Add `DeletionPolicy` and `UpdateReplacePolicy` on stateful resources
|
|
- ✅ **Do:** Use `cfn-lint` and `cfn-nag` in CI pipelines
|
|
- ❌ **Don't:** Hardcode ARNs or account IDs — use `!Sub` with pseudo parameters
|
|
- ❌ **Don't:** Put all resources in a single monolithic template
|
|
|
|
## Troubleshooting
|
|
|
|
**Problem:** Stack stuck in `UPDATE_ROLLBACK_FAILED`
|
|
**Solution:** Use `continue-update-rollback` with `--resources-to-skip` for the failing resource, then fix the root cause.
|