Added ability to show dry-run plan in PR.

Author: patcon

.github/workflows/domain-plan.yml

@@ -0,0 +1,57 @@
+on:
+  pull_request_target:
+defaults:
+  run:
+    shell: bash
+jobs:
+  test-and-comment:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout main
+        uses: actions/checkout@v2
+      - name: Checkout config files from PR
+        id: prhead
+        run: |
+          # Set $_sha to the first 7 char of PR head SHA
+          _sha="$(echo "${{ github.event.pull_request.head.sha }}" | cut -c 1-7)"
+          # Fetch PR head commit
+          git fetch origin refs/pull/${{ github.event.pull_request.number }}/head
+          # List changed config files in PR head
+          _files="$(git diff --name-only HEAD $_sha | grep "\.yaml$")"
+          # Checkout config files from PR head commit
+          if [ -n "$_files" ]; then git checkout "$_sha" -- $_files; fi
+          # Set output 'sha' to $_sha
+          echo "::set-output name=sha::${_sha}"
+      - name: Test changes to DNS config
+        id: octodns-sync
+        uses: solvaholic/octodns-sync@main
+        with:
+          config_path: config.yaml
+      - name: Get plan output
+        id: plan
+        run: |
+          # Parse plan output into $_plan
+          _plan="$(cat ${GITHUB_WORKSPACE}/octodns-sync.plan)"
+          _plan="${_plan//'%'/'%25'}"
+          _plan="${_plan//$'\n'/'%0A'}"
+          _plan="${_plan//$'\r'/'%0D'}"
+          # Set output 'plan' to $_plan
+          echo "::set-output name=plan::${_plan}"
+      - name: Find Comment
+        uses: peter-evans/find-comment@v1
+        id: find-comment
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: 'github-actions[bot]'
+          body-includes: Automatically generated by octodns-sync
+      - name: Add or update PR comment
+        if: ${{ github.event_name != 'workflow_dispatch' }}
+        uses: peter-evans/create-or-update-comment@v1
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
+          body: |
+            ## OctoDNS Plan for `${{ steps.prhead.outputs.sha }}`
+            ${{ steps.plan.outputs.plan }}
+            Automatically generated by octodns-sync
+          edit-mode: replace

.github/workflows/domain-sync.yml

@@ -21,7 +21,7 @@ jobs:
       - uses: actions/checkout@v2
 
       - name: Publish
-        uses: solvaholic/octodns-sync@v2.1.2
+        uses: solvaholic/octodns-sync@main
         with:
           config_path: config.yaml
           doit: '--doit'