terraform-validate

name	terraform-validate
description	Validate Terraform modules and configurations across CPP infrastructure repos. Use when checking Terraform code, reviewing infrastructure changes, or verifying module consistency.

Terraform Validate

Validates Terraform modules and configurations across CPP infrastructure repositories for consistency, security, and best practices.

When to Use

• User asks to "validate terraform", "check this module", "review infrastructure changes"
• User is modifying a cpp-terraform-* or cpp-module-terraform-* repo
• User wants to verify state backend configuration
• User wants to check variable naming conventions across modules

Process

Step 1: Identify Module Type

Prefix	Type	Purpose
cpp-module-terraform-azurerm-*	Reusable module	Shared building blocks consumed by other Terraform repos
cpp-terraform-azurerm-*	Root module	Environment-specific infrastructure provisioning
cpp-terraform-network	Network	VNet, subnet, NSG, peering configuration
cpp-automation-terraform	Automation	Terraform automation and orchestration

Step 2: Validate Structure

Every Terraform repo should have:

├── main.tf                    # Primary resource definitions
├── variables.tf               # Input variable declarations
├── outputs.tf                 # Output value declarations
├── versions.tf                # Provider and Terraform version constraints
├── README.md                  # Auto-generated by terraform-docs
├── .pre-commit-config.yaml    # Pre-commit hooks
├── .terraform-version         # tfversion pinning
└── vars/                      # Environment-specific tfvars (root modules only)
    ├── dev.tfvars
    ├── sit.tfvars
    ├── ste.tfvars
    ├── nft.tfvars
    ├── prp.tfvars
    └── prd.tfvars

Step 3: Validation Checks

Variable Declarations

• All variables have description field
• All variables have type constraint
• Sensitive variables marked with sensitive = true
• Default values only for optional variables
• Variable names use snake_case

Resource Configuration

• All resources have consistent tagging (environment, team, service)
• Resource names follow CPP naming convention: {resource-type}-{env}-{purpose}
• No hardcoded values that should be variables
• Lifecycle rules specified where appropriate (prevent_destroy for stateful resources)

State Backend

• Backend configuration uses Azure Storage Account
• Non-live state: samdvshared01 in RG-MDV-SHARED-01
• Live state: sampdshared01 in RG-MPD-SHARED-01
• State container names are unique per workspace

Security

• No secrets in .tf files or .tfvars (use Key Vault references)
• NSG rules follow least-privilege principle
• Private endpoints used for Azure PaaS services
• Managed identities preferred over service principals
• No * in RBAC role assignments

Pre-commit Hooks

• .pre-commit-config.yaml present
• Hooks include: terraform-fmt, terraform-validate, terraform-docs, tflint
• Hook versions are current

Step 4: Environment Consistency

For root modules with per-environment tfvars:

1. Read all vars/*.tfvars files
2. Verify each environment defines the same set of variables
3. Flag any environment-specific variables missing from other environments
4. Check that production values are appropriately different from non-prod (e.g., larger SKUs, more replicas)

Step 5: Module Dependency Check

For root modules that consume reusable modules:

1. Check module blocks for source references
2. Verify module versions are pinned (not ref=main)
3. Check if newer versions of consumed modules are available
4. Verify required input variables are provided

Step 6: Generate Report

## Terraform Validation Report: [module-name]

### Structure
- [✅/❌] Standard file layout
- [✅/❌] Pre-commit hooks configured
- [✅/❌] README auto-generated

### Variables
| Name | Type | Description | Sensitive | Default | Status |
|------|------|-------------|-----------|---------|--------|

### Security
- [✅/❌] No hardcoded secrets
- [✅/❌] Private endpoints used
- [✅/❌] Managed identities preferred

### Environment Consistency
| Variable | dev | sit | ste | nft | prp | prd |
|----------|-----|-----|-----|-----|-----|-----|

### Issues
- [severity] [description] — suggested fix

CPP-Specific Infrastructure Patterns

AKS Clusters

• System + Worker + Prometheus node pools
• Azure CNI networking with Calico network policy
• OIDC issuer enabled for workload identity
• Cluster naming: {env}-cs{stack}cl{cluster}

PostgreSQL

• Flexible Server (not single server)
• Per-context databases (hearing_db, resulting_db, etc.)
• Admin credentials from Key Vault
• Read-only user for reporting (pgreadonly)

Service Bus

• Per-environment namespace
• Topics per bounded context
• Dead-letter queues configured
• Max delivery count and TTL set per subscription

Key Vault

• Per-environment vaults
• CSI driver for pod secret injection
• Secret rotation enabled