ci: Automatically push the modified files if static UI files need to be updated

This is to reduce the maintainance overhead. Instead of just warning to regenerate the UI files (which the job already knows about), it makes much sense to just push the changes to the PR.

Author: rm3l

.github/workflows/check-generated-files.yaml

@@ -1,15 +1,40 @@
 name: check-generated-files
 on:
-  pull_request:
+  # pull_request_target needed to be able to commit and push bundle diffs to external fork PRs.
+  # But we included a manual authorization safeguard to prevent PWN requests. See the 'authorize' job below.
+  pull_request_target:
     branches:    
       - main
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.number }}
+  cancel-in-progress: true
+
 jobs:
+  authorize:
+    # The 'external' environment is configured with the odo-maintainers team as required reviewers.
+    # All the subsequent jobs in this workflow 'need' this job, which will require manual approval for PRs coming from external forks.
+    # TODO(rm3l): list of authorized users that do not require manual review comes from the maintainers team and various robot accounts that handle automation in the repo => find a better way not to hardcode this list!
+    environment:
+      ${{ (github.event.pull_request.head.repo.full_name == github.repository ||
+      contains(fromJSON('["odo-robot[bot]", "dependabot[bot]", "openshift-ci[bot]", "openshift-merge-robot", "openshift-ci-robot", "feloy", "kadel", "rm3l", "valaparthvi", "ritudes"]'), github.actor)) &&
+      'internal' || 'external' }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo ✓
+
   check-ui-static-files:
+    needs: authorize
     runs-on: ubuntu-22.04
+    permissions:
+      contents: write
+      pull-requests: write
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          repository: ${{github.event.pull_request.head.repo.full_name}}
+          ref: ${{ github.event.pull_request.head.ref }}
 
       - name: Generate static files for UI
         run: make ui-static
@@ -22,7 +47,28 @@ jobs:
         id: verify-changed-files
 
       - name: Some files have changed
-        if: steps.verify-changed-files.outputs.files_changed == 'true'
+        if: ${{ !cancelled() && steps.verify-changed-files.outputs.files_changed == 'true' }}
         run: |
-          echo "::error Changed files: ${{ steps.verify-changed-files.outputs.changed_files }} -- Please regenerate with make ui-static / make prebuild"
-          exit 1
+          echo "::warning Changed files: ${{ steps.verify-changed-files.outputs.changed_files }} -- Regenerating with make ui-static / make prebuild"
+          git config user.name 'github-actions[bot]'
+          git config user.email 'github-actions[bot]@users.noreply.github.com'
+          git fetch --prune
+          git pull --rebase --autostash
+          git add -A .
+          git commit \
+            -m "Regenerate static UI files" \
+            -m "Co-authored-by: $GITHUB_ACTOR <[email protected]>"
+          git push
+
+      - name: Comment on PR if bundle manifests were updated
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+        if: ${{ !cancelled() && steps.verify-changed-files.outputs.files_changed == 'true' }}
+        continue-on-error: true
+        with:
+          script: |
+            await github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: '⚠️ <b>Static UI files regenerated!</b><br/><br/>Those changes should have been pushed automatically to your PR branch.'
+            })