Scaffold terraform

Scaffold Terraform Project

Generate a production-ready Terraform project following established CI/CD patterns. Read the scaffold-project skill first for standard files (README, AGENTS.md, LICENSE, CONTRIBUTING.md, llms.txt).

When to Use

• Creating a new infrastructure-as-code repository
• Adding CI/CD to an existing Terraform project
• Standardizing a Terraform project to match org conventions

Generated Files

.github/workflows/terraform.yml

name: Terraform

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

concurrency:
  group: terraform-${{ github.ref }}
  cancel-in-progress: false

permissions:
  contents: read
  id-token: write
  pull-requests: write

env:
  AWS_REGION: ${{ secrets.AWS_REGION }}

jobs:
  plan:
    name: Terraform Plan
    runs-on: ubuntu-latest
    outputs:
      has_changes: ${{ steps.plan.outputs.has_changes }}
    steps:
      - uses: actions/checkout@v4

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          role-to-assume: ${{ secrets.AWS_ROLE_ARN }}
          aws-region: ${{ secrets.AWS_REGION }}

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: 1.6.0
          terraform_wrapper: false

      - name: Terraform Init
        run: terraform init

      - name: Terraform Format Check
        run: terraform fmt -check
        continue-on-error: true

      - name: Terraform Validate
        run: terraform validate

      - name: Terraform Plan
        id: plan
        run: |
          terraform plan -no-color -out=tfplan -detailed-exitcode 2>&1 | tee plan_output.txt || exit_code=$?
          if [ "${exit_code:-0}" -eq 2 ]; then
            echo "has_changes=true" >> $GITHUB_OUTPUT
          else
            echo "has_changes=false" >> $GITHUB_OUTPUT
          fi
          if [ "${exit_code:-0}" -eq 1 ]; then
            exit 1
          fi

      - name: Upload Plan
        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
        uses: actions/upload-artifact@v4
        with:
          name: tfplan
          path: tfplan
          retention-days: 1

      - name: Comment PR with Plan
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const plan = fs.readFileSync('plan_output.txt', 'utf8');
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });
            const botComment = comments.find(comment =>
              comment.user.type === 'Bot' && comment.body.includes('Terraform Plan')
            );
            const truncatedPlan = plan.length > 60000
              ? plan.substring(0, 60000) + '\n\n... (truncated)'
              : plan;
            const body = `## Terraform Plan\n<details>\n<summary>Click to expand plan output</summary>\n\n\`\`\`hcl\n${truncatedPlan}\n\`\`\`\n</details>\n\n**Workflow Run:** [View Details](${context.serverUrl}/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId})`;
            if (botComment) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner, repo: context.repo.repo,
                comment_id: botComment.id, body
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner, repo: context.repo.repo,
                issue_number: context.issue.number, body
              });
            }

      - name: Plan Summary
        run: |
          echo "## Terraform Plan" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo '```' >> $GITHUB_STEP_SUMMARY
          cat plan_output.txt >> $GITHUB_STEP_SUMMARY
          echo '```' >> $GITHUB_STEP_SUMMARY

  apply:
    name: Terraform Apply
    needs: plan
    if: github.ref == 'refs/heads/main' && github.event_name == 'push' && needs.plan.outputs.has_changes == 'true'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          role-to-assume: ${{ secrets.AWS_ROLE_ARN }}
          aws-region: ${{ secrets.AWS_REGION }}

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: 1.6.0

      - name: Terraform Init
        run: terraform init

      - name: Download Plan
        uses: actions/download-artifact@v4
        with:
          name: tfplan

      - name: Terraform Apply
        run: terraform apply -auto-approve tfplan

      - name: Terraform Output Summary
        run: |
          echo "## Terraform Apply Complete" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "Infrastructure has been updated successfully." >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "### Outputs" >> $GITHUB_STEP_SUMMARY
          terraform output -no-color >> $GITHUB_STEP_SUMMARY 2>/dev/null || echo "No outputs defined" >> $GITHUB_STEP_SUMMARY

No separate ci.yml + release.yml. Terraform uses a single terraform.yml with plan-on-PR and apply-on-push.

Common Commands

No justfile. Terraform CLI is the native tool:

terraform init                # initialize
terraform fmt -recursive      # format
terraform validate            # validate
terraform plan                # plan changes
terraform apply               # apply changes
terraform output              # show outputs

For multi-environment setups (dev/staging/prod workspaces, multiple state files), add a justfile to manage environment switching and orchestration.

.envrc

# terraform/kubectl/helm come from Homebrew/apt. Use this file for AWS/GCP env vars.
dotenv

Project Layout

main.tf           # primary resources
variables.tf      # input variables
outputs.tf        # output values
providers.tf      # provider configuration
backend.tf        # state backend (S3)
terraform.tfvars  # variable values (NOT committed if secrets)

Required GitHub Secrets

Secret	Purpose
AWS_ROLE_ARN	IAM role ARN for OIDC assumption
AWS_REGION	AWS region (e.g., us-east-1)

Gotchas

• cancel-in-progress: false never cancel a running Terraform operation
• terraform_wrapper: false in plan job to get raw exit codes (exit code 2 = changes detected)
• Plan is saved as artifact and downloaded for apply. Ensures apply matches what was planned
• PR comments truncate at 60k chars to stay within GitHub's limits
• OIDC auth (id-token: write + aws-actions/configure-aws-credentials). No long-lived AWS keys
• terraform fmt -check uses continue-on-error: true. Warns but doesn't block
• No sr.yaml or semantic release. Infrastructure changes are applied directly, not versioned/tagged
• Single concurrency group prevents concurrent applies that could corrupt state