Terraform Modules

Folder: .github/skills/tsh-implementing-terraform-modules/ Used by: DevOps Engineer

Provides patterns for building reusable Terraform modules for AWS, Azure, and GCP infrastructure following IaC best practices.

Module Structure

modules/
  <module-name>/
    main.tf          # Core resources
    variables.tf     # Input variables with descriptions and defaults
    outputs.tf       # Output values for consumers
    versions.tf      # Provider and Terraform version constraints
    README.md        # Usage documentation

Design Principles

• Composable — Modules should be combined to build larger systems.
• Configurable — Use variables for all environment-specific values.
• Documented — Every variable and output has a description.
• Versioned — Pin module versions in consumers; use semantic versioning.

Naming & Tagging

Convention	Example
Resources	<project>-<env>-<service>-<resource>
Variables	Snake case with descriptive names
Tags	Project, Environment, Team, CostCenter, ManagedBy

Safety

• Always run terraform plan before terraform apply.
• Use remote state with locking (S3 + DynamoDB, GCS, Azure Blob).
• Enable prevent_destroy lifecycle rules for critical resources.
• Include cost estimates in every proposal.

Connected Skills

• tsh-optimizing-cloud-cost — Cost estimation and optimization.
• tsh-managing-secrets — Secure credential management in Terraform.