Github workflow to parse JIRA ticket key from branch name and add link to JIRA ticket in PR comment

add-jira-link-to-pr.yml

# set JIRA_BASE_URL in env section
# put this file in .github/workflow
# done.

name: Add JIRA Link to PR

on:
  pull_request:
    types:
      - opened

env:
  JIRA_BASE_URL: LINK_TO_YOUR_JIRA # probably something like: https://<YOUR_COMPANY>.atlassian.net/
  PR_BRANCH: ${{ github.event.pull_request.head.ref }}

jobs:
  add-jira-link:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2

      - name: Extract JIRA Key
        id: extract-jira-key
        run: |
          echo "PR_BRANCH: $PR_BRANCH"
          JIRA_KEY=$(echo $PR_BRANCH | grep -Eo '[A-Z]+-[0-9]+')
          echo "::set-output name=jira_key::$JIRA_KEY"

      - name: Add JIRA Link to PR
        if: steps.extract-jira-key.outputs.jira_key != ''
        run: |
          JIRA_KEY="${{ steps.extract-jira-key.outputs.jira_key }}"
          JIRA_LINK="$JIRA_BASE_URL/browse/$JIRA_KEY"
          gh pr comment ${{ github.event.pull_request.number }} -b "🔗 Link to JIRA: [$JIRA_KEY]($JIRA_LINK)"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}