backport.yaml

name: Backport

on:
  pull_request_target:
    types: ["labeled", "closed"]


env:
  GITHUB_BRANCH: ${{ github.ref_name }} 

jobs:
  backport:
    name: Backport PR
    runs-on: ubuntu-latest
    if: |
      github.event.pull_request.merged == true
      && contains(github.event.pull_request.labels.*.name, 'auto-backport')
      && (
        (github.event.action == 'labeled' && github.event.label.name == 'auto-backport')
        || (github.event.action == 'closed')
      )
    outputs:
      BEFORE_BACKPORTS: ${{ steps.count_prs.outputs.pr_count }}
    steps:

      - name: Retrieve Credentials
        id: import-secrets
        uses: hashicorp/vault-action@v3.0.0
        with:
          url: https://vault.prism.spectrocloud.com
          method: approle
          roleId: ${{ secrets.VAULT_ROLE_ID }}
          secretId: ${{ secrets.VAULT_SECRET_ID }}
          secrets: /providers/github/organizations/spectrocloud/token?org_name=spectrocloud token | VAULT_GITHUB_TOKEN

      - name: Count PRs created by vault-token-factory-spectrocloud
        id: count_prs
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          PR_COUNT=$(curl -s -H "Authorization: token $GITHUB_TOKEN" \
            "https://api.github.com/repos/${{ github.repository }}/pulls?state=open&per_page=100" | \
            jq '[.[] | select(.user.login == "vault-token-factory-spectrocloud[bot]")] | length')
          echo "Number of PRs created by vault-token-factory-spectrocloud: $PR_COUNT"
          echo "pr_count=$PR_COUNT" >> $GITHUB_OUTPUT

      - name: Determine branch name
        id: extract_branch
        run: |
          if [ "${{ github.event_name }}" = "pull_request_target" ]; then
            echo "GITHUB_BRANCH=${{ github.head_ref }}" >> $GITHUB_ENV
          else
            echo "GITHUB_BRANCH=${{ github.ref_name }}" >> $GITHUB_ENV
          fi

      - name: Check for backport labels
        id: check_labels
        run: |-
          labels='${{ toJSON(github.event.pull_request.labels.*.name) }}'
          matched=$(echo "${labels}" | jq '. | map(select(startswith("backport-"))) | length')
          echo "matched=$matched"
          echo "matched=$matched" >> $GITHUB_OUTPUT


      - name: Backport Action
        uses: sqren/backport-github-action@v9.5.1
        with:
        # We are using a PAT token through our Vault Operator to address the issue of PRs workflows not being triggered
        # Refer to issue https://github.com/sqren/backport-github-action/issues/79 for more details.
          github_token: ${{ steps.import-secrets.outputs.VAULT_GITHUB_TOKEN }}
          auto_backport_label_prefix: backport-
          add_original_reviewers: true

      - name: Info log
        if: ${{ success() }} 
        run: cat ~/.backport/backport.info.log

      - name: Debug log
        id: debug-log
        if: ${{ failure() }}
        run: cat ~/.backport/backport.debug.log

      - name: Verify PR count increment
        id: verify_increment
        env:
          GITHUB_TOKEN: ${{ steps.import-secrets.outputs.VAULT_GITHUB_TOKEN }}
        run: |-
          BEFORE_BACKPORTS=${{ steps.count_prs.outputs.pr_count }}
          NEW_COUNT=$(curl -s -H "Authorization: token $GITHUB_TOKEN" \
            "https://api.github.com/repos/${{ github.repository }}/pulls?state=open&per_page=100" | \
            jq '[.[] | select(.user.login == "vault-token-factory-spectrocloud[bot]")] | length')
          
          MATCHED=${{ steps.check_labels.outputs.matched }}
      
          echo "Before Backports Count: $BEFORE_BACKPORTS"
          echo "New PR Count: $NEW_COUNT"
          echo "Matched Backport Labels: $MATCHED"
      
          if [ $((NEW_COUNT - BEFORE_BACKPORTS)) -eq $MATCHED ]; then
            echo "PR count increased by the expected amount."
            echo "missing_prs=0" >> $GITHUB_OUTPUT
          else
            MISSING_PR_COUNT=$((MATCHED - (NEW_COUNT - BEFORE_BACKPORTS)))
            echo "PR count did not increase by the expected amount."
            echo "missing_prs=$MISSING_PR_COUNT" >> $GITHUB_OUTPUT
            exit 1
          fi
      

      - name: Slack Notification
        if: ${{ failure() }}
        uses: rtCamp/action-slack-notify@v2.3.2
        env:
          SLACK_WEBHOOK: ${{ secrets.SLACK_PRIVATE_TEAM_WEBHOOK }}
          SLACK_USERNAME: "spectromate"
          SLACK_ICON_EMOJI: ":robot_panic:"
          SLACK_COLOR: ${{ job.status }}
          SLACKIFY_MARKDOWN: true
          ENABLE_ESCAPES: true
          SLACK_MESSAGE: 'The backports for branch `${{env.GITHUB_BRANCH}}` in PR [#${{ github.event.pull_request.number }}](${{ github.event.pull_request.html_url }}) failed. Number of missing PRs: `${{ steps.verify_increment.outputs.missing_prs }}`. Review the PR for more details.'