Terraform Skill

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

Quick Reference

# 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	Common errors, debugging
State	state-management.md	Backends, locking, operations
Modules	module-design.md	Module patterns, composition
Security	security.md	Secrets, state security
Proxmox Gotchas	proxmox/gotchas.md	Critical provider issues, workarounds
Proxmox Auth	proxmox/authentication.md	Provider config, API tokens
Proxmox VMs	proxmox/vm-qemu.md	proxmox_vm_qemu resource patterns
Proxmox Errors	proxmox/troubleshooting.md	Proxmox-specific errors
External	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