pr-build-and-preview.yaml

name: Build Container Image and Preview Environment

on:
  workflow_dispatch:
  pull_request:
    branches:
      - '*'

jobs:
  build-container:
    runs-on: ubuntu-latest

    steps:
    - name: Checkout source code
      uses: actions/checkout@v3

    - name: Login to Docker Hub
      uses: docker/login-action@v3
      with:
        username: ${{ secrets.DOCKERHUB_USERNAME }}
        password: ${{ secrets.DOCKERHUB_TOKEN }}

    - name: Build and Push
      uses: docker/build-push-action@v5
      with:
        push: true
        tags: ${{ secrets.DOCKERHUB_USERNAME }}/neon-kube-previews:${{ github.event.pull_request.head.sha }}

  create-preview-environment:
    runs-on: ubuntu-latest

    # Wait for the docker build and push to complete prior to running this job.
    # Technically this could run in parallel, but it doesn't make sense to add
    # a preview URL if the build step fails 
    needs: build-container

    # This permission is required to comment with the preview URL on the PR
    permissions: 
      pull-requests: write 

    steps:
    # Create a new branch on Neon using the PR number in the branch name. This
    # operation is idempotent, so it's effectively a no-op if more commits are
    # push to the original PR
    - name: Create Neon Branch and Compute for PR
      id: create-branch
      uses: neondatabase/create-branch-action@v4
      with:
        api_key: ${{ secrets.NEON_API_KEY }}
        project_id: ${{ secrets.NEON_PROJECT_ID }}
        branch_name: pr-${{ github.event.number }}
        parent: main

    - name: Install the Argo CD CLI
      run: |
        curl -sSL -o argocd-linux-amd64 https://github.com/argoproj/argo-cd/releases/download/v2.8.4/argocd-linux-amd64
        sudo install -m 555 argocd-linux-amd64 /usr/local/bin/argocd
        rm argocd-linux-amd64

    - name: Login to Argo CD
      run: argocd login ${{ secrets.ARGOCD_HOSTNAME }} --username ${{ secrets.ARGOCD_USERNAME }} --password ${{ secrets.ARGOCD_PASSWORD }}

    # Use parameter overrides to set the image tag and database URL:
    # https://argo-cd.readthedocs.io/en/stable/user-guide/parameters/
    - name: Update the Preview Environment with the Neon Branch URL
      run: |
        argocd app set nkp-pr-${{github.event.number}} \
        --parameter database.url=${{ steps.create-branch.outputs.db_url }} \
        --parameter deployment.image.tag=${{ github.event.pull_request.head.sha }}

    - name: Comment on Pull Request
      uses: thollander/actions-comment-pull-request@v2
      with:
        message: |
          :rocket: Preview URL: https://pr-${{github.event.number}}.${{ secrets.PREVIEW_SUBDOMAIN }}
          :octopus: Argo CD URL: https://${{ secrets.ARGOCD_HOSTNAME }}/applications/argocd/nkp-pr-${{github.event.number}}
        # Comment tag allows the action to update an existing comment, if one
        # exists. This prevents spamming the PR with identical comments
        comment_tag: preview-url