feat: try a merge to main w/ backport strategy

.github/workflows/release.yml

@@ -6,13 +6,13 @@ on:
   #   - cron: "0 8 * * *" # daily at 8am, but how to specify branch name?
   push:
     branches:
-      - "main"
       - "release-[0-9].[0-9].x"
       - "k[0-9]*"
 
 permissions:
   contents: write
   pull-requests: write
+  issues: write
 
 jobs:
   release:
@@ -34,22 +34,44 @@ jobs:
         id: release
         with:
           command: manifest
-          default-branch: "${{ steps.extract_branch.outputs.branch }}"
-      - name: Upload Release Artifact
+          default-branch: main
+      - name: tag PR with backport tag
+        shell: bash
+        env:
+          BRANCH: "${{ steps.extract_branch.outputs.branch }}"
+        run:
+          prNumber=$(echo ${{ steps.release.outputs.pr }} | jq -r .number)
+          gh pr edit $prNumber --tag "backport $BRANCH"
+      - name: upload release artifacts
         if: ${{ steps.release.outputs.release_created }}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           gh release upload ${{ steps.release.outputs.tag_name }} ./dist/build.txt
       - name: create release branch from k release
         if: ${{ startsWith(steps.extract_branch.outputs.branch, 'k') && steps.release.outputs.release_created }}
+        id: update_release_config
         run: |
           branch=release-${{ steps.release.outputs.major }}.${{ steps.release.outputs.minor }}.x
           git checkout -b $branch
           mv release-please-config.json tmp.json
           jq '.versioning = "always-bump-patch"' tmp.json > release-please-config.json
           rm tmp.json
-          git add release-please-config.json
-          git commit -m 'chore: release branch config bumps patch'
-          git push -u origin
-      # TODO: announce in #loki-releases if release created
+      - uses: stefanzweifel/git-auto-commit-action@v5
+        if: ${{ steps.update_release_config.outcome == 'success' }}
+        id: create_release_branch
+        with:
+          commit_message: "chore: release branch bumps patch on release"
+          branch: release-${{ steps.release.outputs.major }}.${{ steps.release.outputs.minor }}.x
+          file_pattern: "release-please-config.json"
+          create_branch: true
+      - if: ${{ steps.create_release_branch.outcome == 'success' }}
+        id: created_branch_message
+        env:
+          BRANCH: release-${{ steps.release.outputs.major }}.${{ steps.release.outputs.minor }}.x
+        shell: bash
+        run: |
+          prNumber=$(echo ${{ steps.release.outputs.pr }} | jq -r .number)
+          gh pr comment $prNumber --body "created release branch [$BRANCH](https://github.com/grafana/loki-release/tree/$BRANCH)"
+
+        # TODO: announce in #loki-releases if release created