Iacgen

Max per gate: 10 attempts. If any gate counter hits 10, stop and report failure.

Step-by-Step Execution

STEP 1 — Parse the Business Need

Extract the infrastructure requirement from the user's message. If the request is ambiguous about a critical design choice (e.g., public vs private bucket), ask ONE clarifying question before proceeding.

STEP 2 — Plan the Template

Before writing YAML, silently reason through:

1. Which AWS resource types are needed (e.g., AWS::S3::Bucket, AWS::Lambda::Function)
2. Resource dependency ordering (resources referenced by others come first, or use !Ref)
3. Required properties for each resource type (cfn-lint will catch missing required props)
4. Which resources need IAM roles or policies
5. DeletionPolicy / UpdateReplacePolicy needs
6. Useful Outputs (URLs, ARNs, stack exports)

STEP 3 — Generate the Template

Write the complete CloudFormation YAML. Follow these rules strictly:

1. Start with AWSTemplateFormatVersion: '2010-09-09'
2. Include a Description: field
3. DeletionPolicy and UpdateReplacePolicy are resource-level attributes — place at the same indentation level as Type: and Properties:, NOT inside Properties:
4. Use !Ref, !GetAtt, !Sub, !Join, !Select for cross-resource references
5. No markdown fences, no backticks, no explanatory prose — pure YAML only
6. End with the last property of the last resource (or the Outputs section if present)

STEP 4 — Save the Template

Write the YAML content to: /tmp/iacgen_<unix_timestamp>_iter_<N>.yaml

Use the write file tool. The file must contain raw YAML only.

STEP 5 — Gate 1: YAML Format Validation

python3 {baseDir}/scripts/validate_yaml.py /tmp/iacgen_<timestamp>_iter_<N>.yaml

Read the JSON output:

• {"passed": true} → proceed to Gate 2
• {"passed": false, "details": [...]} → apply feedback, goto Step 3

Feedback logic for Gate 1:

• yaml_attempts 0–1: Fix the specific YAML structural error (indentation, duplicate key)
• yaml_attempts 2–5: Show explicit corrected YAML for the failing lines
• yaml_attempts 6–9: Rewrite the entire affected section from scratch
• yaml_attempts >= 10: Stop, report max_attempts_exceeded at yaml_validation gate

yaml_attempts += 1 after each failure.

STEP 6 — Gate 2: CloudFormation Syntax Validation

python3 {baseDir}/scripts/validate_cfn.py /tmp/iacgen_<timestamp>_iter_<N>.yaml

Read the JSON output:

• {"passed": true} → proceed to Gate 3 (or finish if deployment is skipped)
• {"passed": false, "error_details": [...]} → apply feedback, goto Step 3

Feedback logic for Gate 2:

• cfn_attempts 0–1: Note cfn-lint errors; fix them
• cfn_attempts 2–5: Address every error in error_details explicitly before rewriting
• cfn_attempts 6–9: Consult the documentation URL in each error for exact constraints
• cfn_attempts >= 10: Stop, report max_attempts_exceeded at syntax_validation gate

cfn_attempts += 1 after each failure.

STEP 7 — Gate 3: Live AWS Deployment (optional)

Skip Gate 3 if:

• User says "no deployment", "dry run", or "skip deployment"
• AWS_ACCESS_KEY_ID / AWS_SECRET_ACCESS_KEY / AWS_DEFAULT_REGION are not set

Otherwise:

python3 {baseDir}/scripts/deploy_aws.py /tmp/iacgen_<timestamp>_iter_<N>.yaml

Read the JSON output:

• {"success": true} → done! Report success with stack details.
• {"success": false, "failed_reason": "..."} → apply feedback, goto Step 3

Feedback logic for Gate 3:

• deploy_attempts 0–1: Note the deployment failed; fix the conflicting AWS configuration
• deploy_attempts 2–5: Address the exact failed_reason text explicitly (e.g., "Policy has been blocked by BlockPublicPolicy" → set all 4 PublicAccessBlockConfiguration fields to false)
• deploy_attempts 6–9: Reason through the full AWS service constraint causing the error
• deploy_attempts >= 10: Stop, report max_attempts_exceeded at deployment gate

deploy_attempts += 1 after each failure. iteration += 1 at the end of every failed loop.

Output Format

✅ Success

✅ CloudFormation Template — Generated Successfully
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Iterations  : <N>
Gates passed: YAML ✅  CFN-Lint ✅  Deployment [✅ / ⏭️ skipped]
Saved to    : <path>

<full YAML template>

❌ Failure

❌ IaCGen — Max attempts reached
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Failed at   : <gate name>
Attempts    : YAML <N> / CFN-Lint <N> / Deploy <N>
Last error  : <error message>
Partial file: <path>

Common CloudFormation Pitfalls