Add dogfood GH action (#8451)

.github/workflows/dogfood.yml

@@ -0,0 +1,51 @@
+name: dogfood merge
+# This workflow is triggered on pushes to master and dogfood branches
+on:
+  push:
+  delete:
+    # There is no 'branch:' filter for the delete action,
+    # so we are using 'if:' inside the job instead.
+
+env:
+  SLACK_CHANNEL: team-lang-dotnet
+  SLACK_USERNAME: Dogfood build action
+
+jobs:
+  dogfood_merge:
+    if: >-
+      (github.event_name == 'push' && (github.event.ref == 'refs/heads/master' || startsWith(github.event.ref, 'refs/heads/dogfood/')))
+      || (github.event_name == 'delete' && startsWith(github.event.ref, 'dogfood/'))
+    runs-on: ubuntu-latest
+    name: Update dogfood branch
+    permissions:
+      id-token: write # required for SonarSource/vault-action-wrapper
+    steps:
+      - name: get secrets
+        id: secrets
+        uses: SonarSource/vault-action-wrapper@v2
+        with:
+          secrets: |
+            development/kv/data/slack webhook | SLACK_WEBHOOK;
+      - name: git octopus step
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        id: dogfood
+        uses: SonarSource/gh-action_dogfood_merge@v1
+        with:
+          dogfood-branch: 'dogfood-on-peach'
+      # Use the output from the `dogfood` step
+      - name: Get the name of the dogfood branch and its HEAD SHA1
+        run: echo "The dogfood branch was `${{ steps.dogfood.outputs.dogfood-branch }}` and its HEAD SHA1 was `${{ steps.dogfood.outputs.sha1 }}`"
+      #slack notifications
+      - name: Notify success on Slack
+        uses: Ilshidur/action-slack@1.6.2
+        env:
+          SLACK_WEBHOOK: ${{ fromJSON(steps.secrets.outputs.vault).SLACK_WEBHOOK }}
+          SLACK_OVERRIDE_MESSAGE: 'Dogfood build for `${{ steps.dogfood.outputs.sha1 }}`: *successful*'
+        with:
+          args: 'Succeed to build dogfood branch'
+      - name: Notify failures on Slack
+        uses: Ilshidur/action-slack@1.6.2
+        if: failure()
+        with:
+          args: "Dogfood merge failed by {{ GITHUB_ACTOR }}, see {{ GITHUB_SERVER_URL }}/{{ GITHUB_REPOSITORY }}/actions/runs/{{ GITHUB_RUN_ID }}"