GitHub Actions で Vercel bot みたいなプレビューデプロイをつくる

name: Deploy preview

on:
  push:
    branches:  # branches other than main
      - '*'
      - '!main'

env:
  ENV_NAME: preview-${{ github.ref_name }}  # preview-[branch name]

jobs:
  deploy:
    name: Deploy
    
    runs-on: ubuntu-latest
    
    permissions:
      deployments: write  # bobheadxi/deployments needs this
    
    outputs:
      url: ${{ steps.deploy-url.outputs.url }}
    
    steps:
      - name: Start deployment
        uses: bobheadxi/deployments@v1
        id: deployment
        with:
          step: start
          token: ${{ github.token }}
          env: ${{ env.ENV_NAME }}
      
      # Authenticate and deploy steps...
      
      - name: Deploy
        id: deploy-url
        run: # Output the deployment URL
      
      - name: Update deployment status
        uses: bobheadxi/deployments@v1
        if: always()
        with:
          step: finish
          token: ${{ github.token }}
          status: ${{ job.status }}
          env: ${{ steps.deployment.outputs.env }}
          env_url: ${{ steps.deploy-url.outputs.url }}
          deployment_id: ${{ steps.deployment.outputs.deployment_id }}

  check-if-pr-exists:
    needs: deploy

    name: Check if associated PR exists

    runs-on: ubuntu-latest

    permissions:
      pull-requests: read

    outputs:
      pr-number: ${{ steps.get-pr-number.outputs.pr-number }}

    steps:
      - name: Get associated PRs
        id: prs
        run: >
          echo "::set-output name=pulls::
          $(gh api -H "Accept: application/vnd.github.v3+json" -X GET
          /repos/${{ github.repository }}/pulls -f state=open -f head=${{ github.actor }}:${{ github.ref_name }})"
        env:
          GH_TOKEN: ${{ github.token }}

      - name: Get PR number
        id: get-pr-number
        run: |
          if [ "${{ fromJSON(env.PULL) }}" ]; then
            echo "::set-output name=pr-number::${{ fromJSON(env.PULL).number }}";
          else
            echo "::set-output name=pr-number::0";
          fi
        env:
          PULL: ${{ toJSON(fromJSON(steps.prs.outputs.pulls)[0]) }}

  comment:
    needs:
      - deploy
      - check-if-pr-exists

    name: Comment on PR

    if: needs.check-if-pr-exists.outputs.pr-number != 0

    runs-on: ubuntu-latest

    permissions:
      contents: read        # actions/checkout needs this
      issues: write         # peter-evans/create-or-update-comment needs this
      pull-requests: write  # peter-evans/create-or-update-comment needs this

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

      - name: Find Comment
        uses: peter-evans/find-comment@v2
        id: fc
        with:
          issue-number: ${{ needs.check-if-pr-exists.outputs.pr-number }}
          comment-author: github-actions[bot]
          body-includes: preview

      - name: Get datetime for now
        id: datetime
        run: echo "::set-output name=value::$(date)"
        env:
          TZ: Asia/Tokyo

      - name: Create or update comment
        uses: peter-evans/create-or-update-comment@v2
        with:
          issue-number: ${{ needs.check-if-pr-exists.outputs.pr-number }}
          comment-id: ${{ steps.fc.outputs.comment-id }}
          body: |
            :eyes: Visit the **preview** for this PR (updated for commit ${{ github.sha }}):
            [![View the preview deployment at ${{ needs.deploy.outputs.url }}](https://img.shields.io/badge/-View_Preview-eee)](${{ needs.deploy.outputs.url }})
            <sub>(:clock3: updated at ${{ steps.datetime.outputs.value }})</sub>
          edit-mode: replace

name: Comment on PR about deployment

on:
  pull_request:
    types:
      - opened

env:
  ENV_NAME: preview-${{ github.head_ref }}  # preview-[branch name]

jobs:
  check-if-deployment-exists:
    name: Check if a successful deployment exists

    runs-on: ubuntu-latest

    permissions:
      deployments: read

    env:
      GH_TOKEN: ${{ github.token }}

    outputs:
      state: ${{ steps.get-status.outputs.state }}
      url: ${{ steps.get-status.outputs.url }}

    steps:
      - name: Get associated deployments
        id: get-deployments
        run: >
          echo "::set-output name=deployments::
          $(gh api -H "Accept: application/vnd.github.v3+json"
          /repos/${{ github.repository }}/deployments?environment=${{ env.ENV_NAME }})"

      - name: Get statuses of the deployment
        id: get-statuses
        run: >
          echo "::set-output name=statuses::
          $(gh api -H "Accept: application/vnd.github.v3+json"
          /repos/${{ github.repository }}/deployments/${{ env.DEP_ID }}/statuses)"
        env:
          DEP_ID: ${{ fromJSON(steps.get-deployments.outputs.deployments)[0].id }}

      - name: Get latest status of the deployment
        id: get-status
        run: |
          echo "::set-output name=state::${{ fromJSON(env.STATUS).state }}"
          echo "::set-output name=url::${{ fromJSON(env.STATUS).environment_url }}"
        env:
          STATUS: ${{ toJSON(fromJSON(steps.get-statuses.outputs.statuses)[0]) }}

  comment:
    needs: check-if-deployment-exists

    name: Comment on PR

    if: needs.check-if-deployment-exists.outputs.state != null

    runs-on: ubuntu-latest

    permissions:
      contents: read
      issues: write
      pull-requests: write

    steps:
      - name: Checkout
        uses: actions/checkout@v3
      
      - name: Get datetime for now
        id: datetime
        run: echo "::set-output name=value::$(date)"
        env:
          TZ: Asia/Tokyo

      - name: Comment on PR if the deployment has completed
        if: needs.check-if-deployment-exists.outputs.state == 'success'
        uses: peter-evans/create-or-update-comment@v2
        with:
          issue-number: ${{ github.event.pull_request.number }}
          body: |
            :eyes: Visit the **preview** for this PR (updated for commit ${{ github.sha }}):
            [![View the preview deployment at ${{ needs.check-if-deployment-exists.outputs.url }}](https://img.shields.io/badge/-View_Preview-eee)](${{ needs.check-if-deployment-exists.outputs.url }})
            <sub>(:clock3: updated at ${{ steps.datetime.outputs.value }})</sub>

      - name: Create comment if the deployment has not completed
        if: needs.check-if-deployment-exists.outputs.state == 'in_progress'
        uses: peter-evans/create-or-update-comment@v2
        with:
          issue-number: ${{ github.event.pull_request.number }}
          body: |
            :hourglass_flowing_sand: preview deployment is ongoing...