terraform.yml

name: terraform-infra-provisioning

on:
  workflow_dispatch:
  push:
    branches: [ '*' ]
    paths-ignore:
      - '**/README.md'
  pull_request:
    branches: ["main"]
    paths-ignore:
      - '**/README.md'

permissions: read-all
#--------------------------
#
# PLEASE READ: Add a GitHub Actions variable 'INFRACOST_SCAN_TYPE' and set the value to either 'hcl_code' or 'tf_plan' depending on what type of Infracost scan desired.
#
#--------------------------
jobs:
  terraform:
    name: 'continuous-integration'
    runs-on: ubuntu-latest
    environment: production
    permissions:
      contents: read
      id-token: write
      pull-requests: write
    # Use the Bash shell regardless whether the GitHub Actions runner is ubuntu-latest, macos-latest, or windows-latest
    defaults:
      run:
        shell: bash

    steps:
    # Checkout the repository to the GitHub Actions runner
    - name: Checkout
      uses: actions/checkout@v3

    - name: Configure AWS Credentials Action For GitHub Actions
      uses: aws-actions/configure-aws-credentials@v1-node16
      with:
        role-to-assume: ${{ secrets.IAM_ROLE }}
        role-session-name: AWSSession
        aws-region: us-east-2

    # Install the latest version of Terraform CLI and configure the Terraform CLI configuration file with a Terraform Cloud user API token
    - name: Setup Terraform
      uses: hashicorp/setup-terraform@v1

    - name: Setup Infracost
      uses: infracost/actions/setup@v2
      # See https://github.com/infracost/actions/tree/master/setup for other inputs
      # If you can't use this action, see Docker images in https://infracost.io/cicd
      with:
        api-key: ${{ secrets.INFRACOST_API_KEY }}
      if: github.event_name == 'pull_request'

      # Checkout the base branch of the pull request (e.g. main/master).
    - name: Checkout base branch
      if: ${{ (github.event_name == 'pull_request') && (vars.INFRACOST_SCAN_TYPE  == 'hcl_code') }}
      uses: actions/checkout@v3
      with:
        ref: '${{ github.event.pull_request.base.ref }}'
      
    # Generate Infracost JSON file as the baseline.
    - name: Generate Infracost cost estimate baseline
      if: ${{ (github.event_name == 'pull_request') && (vars.INFRACOST_SCAN_TYPE  == 'hcl_code') }}
      run: |
        infracost breakdown --path=. \
                            --format=json \
                            --out-file=/tmp/infracost-base.json

    # Checkout the current PR branch so we can create a diff.
    - name: Checkout PR branch
      if: ${{ (github.event_name == 'pull_request') && (vars.INFRACOST_SCAN_TYPE  == 'hcl_code') }}
      uses: actions/checkout@v3

    # Generate an Infracost diff and save it to a JSON file.
    - name: Generate Infracost diff
      if: ${{ (github.event_name == 'pull_request') && (vars.INFRACOST_SCAN_TYPE  == 'hcl_code') }}
      run: |
        infracost diff --path=. \
                        --format=json \
                        --compare-to=/tmp/infracost-base.json \
                        --out-file=/tmp/infracost.json
  
    # Initialize a new or existing Terraform working directory by creating initial files, loading any remote state, downloading modules, etc.
    - name: Terraform Init
      id: init
      run: terraform init

    # Checks that all Terraform configuration files adhere to a canonical format
    - name: Terraform Format
      id: fmt
      run: terraform fmt -check
    # Checks that all Terraform configuration files are correctly written
    - name: Terraform Validate
      id: validate
      run: terraform validate -no-color
    # Generates an execution plan for Terraform
    - name: Terraform Plan
      id: plan
      if: github.ref != 'refs/heads/main' || github.event_name == 'pull_request'
      run: |
        terraform plan -no-color -input=false \
        -out=TFplan.JSON
      continue-on-error: true

    # Generate an Infracost diff and save it to a JSON file.
    - name: Generate Infracost diff
      if:  ${{ (github.event_name == 'pull_request') && (vars.INFRACOST_SCAN_TYPE  == 'tf_plan') }}
      run: |
        infracost diff --path=TFplan.JSON \
                        --format=json \
                        --out-file=/tmp/infracost.json

    - name: Post Infracost estimate
      if: github.event_name == 'pull_request'
      run: |
          infracost comment github --path=/tmp/infracost.json \
                                    --repo=$GITHUB_REPOSITORY \
                                    --github-token=${{github.token}} \
                                    --pull-request=${{github.event.pull_request.number}} \
                                    --show-skipped \
                                    --behavior=update

    - name: Post Terraform Plan output
      uses: actions/github-script@v6
      if: github.event_name == 'pull_request'
      env:
        PLAN: "terraform\n${{ steps.plan.outputs.stdout }}"
      with:
        github-token: ${{ secrets.GITHUB_TOKEN }}
        script: |
          const output = `#### Terraform Format and Style 🖌\`${{ steps.fmt.outcome }}\`
          #### Terraform Initialization ⚙️\`${{ steps.init.outcome }}\`
          #### Terraform Plan 📖\`${{ steps.plan.outcome }}\`
          #### Terraform Validation 🤖\`${{ steps.validate.outcome }}\`

          <details><summary>Show Plan</summary>

          \`\`\`\n
          ${process.env.PLAN}
          \`\`\`

          </details>

          *Pushed by: @${{ github.actor }}, Action: \`${{ github.event_name }}\`*`;

          github.rest.issues.createComment({
            issue_number: context.issue.number,
            owner: context.repo.owner,
            repo: context.repo.repo,
            body: output
          })

    # On push to "main", build or change infrastructure according to Terraform configuration files
    # Note: It is recommended to set up a required "strict" status check in your repository for "Terraform Cloud". See the documentation on "strict" required status checks for more information: https://help.github.com/en/github/administering-a-repository/types-of-required-status-checks
    - name: Terraform Apply
      if: github.ref == 'refs/heads/main'
      run: terraform apply -auto-approve -input=false