Terraform CLI

When to Use

• Validating Terraform configurations
• Planning infrastructure changes
• Applying infrastructure changes (with approval)
• Security scanning IaC

Prerequisites

• Terraform >= 1.5.0 installed
• Azure CLI authenticated
• Backend storage account accessible
• Environment variables: ARM_SUBSCRIPTION_ID, ARM_TENANT_ID

Commands

Format & Validate

# Check formatting
terraform fmt -check -recursive -diff

# Apply formatting
terraform fmt -recursive

# Validate configuration
terraform init -backend=false
terraform validate

Planning

# Initialize with backend
terraform init -reconfigure

# Create plan
terraform plan \
  -var-file=environments/${ENVIRONMENT}.tfvars \
  -out=tfplan \
  -detailed-exitcode

# Show plan in JSON
terraform show -json tfplan | jq '.resource_changes'

Security Scanning

# TFSec scan
tfsec . --format=json --out=tfsec-results.json

# Checkov scan
checkov -d . --output-file=checkov-results.json --output=json

State Operations (Read-Only)

# List resources
terraform state list

# Show resource details
terraform state show 'azurerm_kubernetes_cluster.main'

Best Practices

1. ALWAYS run terraform fmt before committing
2. ALWAYS run terraform validate before planning
3. NEVER commit .tfstate files
4. ALWAYS use -out flag for plans to review
5. Use workspaces for environment separation
6. Enable state locking with Azure blob lease

Output Format

Provide structured output:

1. Command executed with full parameters
2. Exit code (0=success, 1=error, 2=changes pending)
3. Summary: resources to add/change/destroy
4. Warnings or errors with line references
5. Recommendations for next steps

Integration with Agents

Used by: @terraform, @security, @test

Source: paulanunes85/three-horizons-accelerator — distributed by TomeVault.