name: plan-examples

on:
  # Review https://securitylab.github.com/research/github-actions-preventing-pwn-requests/ and better understand the risks of using pull_request_target before making major changes to this workflow.
  pull_request_target:
    branches:
      - main
  workflow_dispatch:

concurrency:
  group: "${{ github.workflow }} @ ${{ github.event.pull_request.head.label || github.head_ref || github.ref }}"
  cancel-in-progress: true

jobs:
  getExampleDirectories:
    name: Get example directories
    runs-on: ubuntu-latest
    # Do not remove environment setup without considering changes to pull_request_target and checkout of PR, as it may lead to checks running automatically against malicious code in PRs.
    environment: Observability Test
    # Skip running on forks since it won't have access to secrets
    if: github.repository == 'aws-observability/terraform-aws-observability-accelerator'
    outputs:
      directories: ${{ steps.dirs.outputs.directories }}
    steps:
      # Be careful not to change this to explicit checkout from PR ref/code, as below we run a python code that may change from the PR code.
      - name: Checkout
        uses: actions/checkout@v3

      - name: Get Terraform directories for evaluation
        id: dirs
        run: |
          DIRS=$(python3 .github/workflows/plan-examples.py)
          echo "directories=$DIRS" >> $GITHUB_OUTPUT

  plan:
    name: Plan examples
    needs: getExampleDirectories
    runs-on: ubuntu-latest
    # Skip running on forks since it won't have access to secrets
    if: github.repository == 'aws-observability/terraform-aws-observability-accelerator'

    # These permissions are needed to interact with GitHub's OIDC Token endpoint.
    permissions:
      id-token: write
      contents: read
    strategy:
      fail-fast: false
      matrix:
        directory: ${{ fromJson(needs.getExampleDirectories.outputs.directories) }}

    steps:
      - name: Remove default Terraform
        run: rm -rf $(which terraform)

      - name: checkout-merge
        if: "contains(github.event_name, 'pull_request')"
        uses: actions/checkout@v3
        with:
          ref: refs/pull/${{github.event.pull_request.number}}/merge

      - name: checkout
        if: "!contains(github.event_name, 'pull_request')"
        uses: actions/checkout@v3

      - uses: dorny/paths-filter@v2
        id: changes
        with:
          # Need to check not only the example directory
          # but also the supporting module(s) code
          # for plans (not for pre-commit)
          filters: |
            src:
              - '${{ matrix.directory }}/**/*.(tf|yml|yaml)'
              - 'modules/**/*.(tf|yml|yaml)'
              - '*.tf'

      - name: Configure AWS credentials from Test account
        uses: aws-actions/configure-aws-credentials@v1
        if: steps.changes.outputs.src== 'true'
        with:
          role-to-assume: ${{ secrets.ROLE_TO_ASSUME }}
          aws-region: us-west-2
          role-duration-seconds: 3600
          role-session-name: GithubActions-Session

      - name: Terraform Job
        uses: hashicorp/setup-terraform@v2
        if: steps.changes.outputs.src== 'true'
        with:
          terraform_version: 1.2.9

      - if: steps.changes.outputs.src== 'true'
        run: terraform version

      - name: Terraform Init
        if: steps.changes.outputs.src== 'true'
        run: terraform init -reconfigure
        working-directory: ${{ matrix.directory }}

      - name: Terraform Plan
        if: steps.changes.outputs.src== 'true'
        working-directory: ${{ matrix.directory }}
        run: terraform plan -no-color