Terraform Skill

# Terraform Skill for Claude

Diagnose-first guidance for Terraform and OpenTofu. Core file is a workflow; depth lives in references loaded on demand.

## Response Contract

Every Terraform/OpenTofu response must include:

1. **Assumptions & version floor** — runtime (`terraform` or `tofu`), exact version, providers, state backend, execution path (local/CI/Cloud/Atlantis), environment criticality. State assumptions explicitly if the user did not provide them.
2. **Risk category addressed** — one or more of: identity churn, secret exposure, blast radius, CI drift, compliance gaps, state corruption, provider upgrade risk, testing blind spots.
3. **Chosen remediation & tradeoffs** — what was chosen, what was traded off, why.
4. **Validation plan** — exact commands (`fmt -check`, `validate`, `plan -out`, policy check) tailored to runtime and risk tier.
5. **Rollback notes** — for any destructive or state-mutating change: how to undo, what evidence to keep.

Never recommend direct production apply without a reviewed plan artifact and approval.

## Workflow

1. **Capture execution context** — runtime+version, provider(s), backend, execution path, environment criticality.
2. **Diagnose failure mode(s)** using the routing table below. If intent spans categories, load both references.
3. **Load only the matching reference file(s)** — do not preload depth the task does not need.
4. **Propose fix with risk controls** — why this addresses the mode, what could still go wrong, guardrails (tests/approvals/rollback).
5. **Generate artifacts** — HCL, migration blocks (`moved`, `import`), CI changes, policy rules.
6. **Validate before finalizing** — run validation commands tailored to risk tier.
7. **Emit the Response Contract** at the end.

## Diagnose Before You Generate

| Failure category | Symptoms | Primary references |
|------------------|----------|--------------------|
| **Identity churn** | Resource addresses shift after refactor, `count` index churn, missing `moved` blocks | [Code Patterns: count vs for_each](references/code-patterns.md#count-vs-for_each-deep-dive), [Code Patterns: moved blocks](references/code-patterns.md#moved-blocks-terraform-11), [Code Patterns: LLM mistakes](references/code-patterns.md#llm-mistake-checklist--code-patterns) |
| **Secret exposure** | Secrets in defaults, state, logs, CI artifacts | [Security & Compliance](references/security-compliance.md), [Code Patterns: write-only](references/code-patterns.md#write-only-arguments-terraform-111), [State Management](references/state-management.md) |
| **Blast radius** | Oversized stacks, shared prod/non-prod state, unsafe applies | [State Management](references/state-management.md), [Module Patterns](references/module-patterns.md) |
| **CI drift** | Local plan ≠ CI plan, apply without reviewed artifact, unpinned versions | [CI/CD Workflows](references/ci-cd-workflows.md), [Code Patterns: versions](references/code-patterns.md#version-management) |
| **Compliance gaps** | Missing policy stage, no approval model, no evidence retention | [Security & Compliance](references/security-compliance.md), [CI/CD Workflows](references/ci-cd-workflows.md) |
| **Testing blind spots** | Plan-only validation of computed values, set-type indexing, mock/real confusion | [Testing Frameworks](references/testing-frameworks.md) |
| **State corruption / recovery** | Stuck lock, backend migration, drift reconciliation | [State Management](references/state-management.md) |
| **Provider upgrade risk** | Breaking-change provider bump, unpinned modules | [Code Patterns: versions](references/code-patterns.md#version-management), [Module Patterns](references/modul