terraform-audit

Terraform Audit Skill

Perform a comprehensive audit of a Terraform codebase across four dimensions: security & compliance, cost optimization, code quality, and architecture design. The audit produces a structured Markdown report with findings classified by severity. Rules are grounded in the CIS AWS Foundations Benchmark and the AWS Well-Architected Framework, with a primary focus on AWS resources.

Description

Perform a comprehensive audit of a Terraform codebase covering four dimensions: security and compliance, cost optimization, code quality, and architecture design. Based on the CIS AWS Foundations Benchmark and the AWS Well-Architected Framework, output a structured Markdown audit report for AWS resources classified by Critical / Important / Minor severity levels.

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Execution Guidelines

• Scan the project structure before auditing; determine scale by the number of .tf files (Small / Medium / Large) and choose the corresponding strategy
• Execute the four dimensions in order: Security -> Cost -> Quality -> Architecture, reading the corresponding sub-module checklist for each
• Every finding must include a severity level, affected file and line number, and specific remediation advice (including HCL code)
• Use the report-template.md template for the report, saved to the project root directory
• When cross-dimensional complementary rules exist (e.g., Multi-AZ in both architecture and cost), annotate the cross-reference context

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Examples

Bad

# S3 bucket with no encryption, no versioning, public access
resource "aws_s3_bucket" "data" {
  bucket = "my-data-bucket"
}

resource "aws_s3_bucket_public_access_block" "data" {
  bucket                  = aws_s3_bucket.data.id
  block_public_acls       = false
  block_public_policy     = false
  ignore_public_acls      = false
  restrict_public_buckets = false
}

✅ Good

resource "aws_s3_bucket" "data" {
  bucket = "${var.project}-${var.environment}-data"
}

resource "aws_s3_bucket_versioning" "data" {
  bucket = aws_s3_bucket.data.id
  versioning_configuration { status = "Enabled" }
}

resource "aws_s3_bucket_server_side_encryption_configuration" "data" {
  bucket = aws_s3_bucket.data.id
  rule {
    apply_server_side_encryption_by_default {
      sse_algorithm     = "aws:kms"
      kms_master_key_id = aws_kms_key.main.arn
    }
  }
}

resource "aws_s3_bucket_public_access_block" "data" {
  bucket                  = aws_s3_bucket.data.id
  block_public_acls       = true
  block_public_policy     = true
  ignore_public_acls      = true
  restrict_public_buckets = true
}