terraform

---
name: terraform
description: |
license: MIT
---

# Terraform Skill

Infrastructure-as-code reference for Terraform configurations, state management, and provider patterns.

## Quick Reference

```bash
# Core workflow
terraform init              # Initialize, download providers
terraform validate          # Syntax validation
terraform fmt -recursive    # Format HCL files
terraform plan              # Preview changes
terraform apply             # Apply changes

# Inspection
terraform state list                    # List resources in state
terraform state show <resource>         # Show resource details
terraform graph | dot -Tsvg > graph.svg # Dependency graph

# Debug
TF_LOG=DEBUG terraform plan 2>debug.log
```

## Core Workflow

```
init → validate → fmt → plan → apply
```

1. **init**: Download providers, initialize backend
2. **validate**: Check syntax and configuration validity
3. **fmt**: Ensure consistent formatting
4. **plan**: Preview what will change (review carefully)
5. **apply**: Execute changes

## Reference Files

Load on-demand based on task:

| Topic | File | When to Load |
|-------|------|--------------|
| Troubleshooting | [troubleshooting.md](references/troubleshooting.md) | Common errors, debugging |
| State | [state-management.md](references/state-management.md) | Backends, locking, operations |
| Modules | [module-design.md](references/module-design.md) | Module patterns, composition |
| Security | [security.md](references/security.md) | Secrets, state security |
| Proxmox Gotchas | [proxmox/gotchas.md](references/proxmox/gotchas.md) | Critical provider issues, workarounds |
| Proxmox Auth | [proxmox/authentication.md](references/proxmox/authentication.md) | Provider config, API tokens |
| Proxmox VMs | [proxmox/vm-qemu.md](references/proxmox/vm-qemu.md) | proxmox_vm_qemu resource patterns |
| Proxmox Errors | [proxmox/troubleshooting.md](references/proxmox/troubleshooting.md) | Proxmox-specific errors |
| External | [external-resources.md](references/external-resources.md) | Official docs, links |

## Validation Checklist

Before `terraform apply`:

- [ ] `terraform init` completed successfully
- [ ] `terraform validate` passes
- [ ] `terraform fmt` applied
- [ ] `terraform plan` reviewed (check destroy/replace operations)
- [ ] Backend configured correctly (for team environments)
- [ ] State locking enabled (if remote backend)
- [ ] Sensitive variables marked `sensitive = true`
- [ ] Provider versions pinned in `terraform.tf`
- [ ] No secrets in version control
- [ ] Blast radius assessed (what could break?)

## Variable Precedence

(highest to lowest)

1. `-var` flag: `terraform apply -var="name=value"`
2. `-var-file` flag: `terraform apply -var-file=prod.tfvars`
3. `*.auto.tfvars` files (alphabetically)
4. `terraform.tfvars` file
5. `TF_VAR_*` environment variables
6. Variable defaults in `variables.tf`