chore(deps): auto-regenerate manifests on Renovate manifests bumps (#4919)

* chore: auto-regenerate manifests on Renovate manifests bumps

Author: czeslavo

.github/workflows/regenerate_on_deps_bump.yaml

@@ -0,0 +1,36 @@
+# This workflow will regenerate the manifests, commit&push them on a PR labeled with `renovate/auto-regenerate`.
+# It's to make sure that Renovate-created PRs that update kustomize dependencies also update the manifests.
+name: Regenerate on deps bump
+
+on:
+  pull_request:
+    types:
+      - labeled
+
+jobs:
+  regenerate:
+    if: contains(github.event.*.labels.*.name, 'renovate/auto-regenerate')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.ref }}
+
+      - name: setup golang
+        uses: actions/setup-go@v4
+        with:
+          go-version-file: go.mod
+
+      - name: regenerate
+        run: make manifests
+
+      - name: commit and push (if changes detected)
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          git config --global user.name "github-actions"
+          git config --global user.email "[email protected]"
+          git add . 
+          git diff-index --quiet HEAD || \
+          git commit -m "chore: regenerate manifests" && \
+          git push origin ${{ github.event.pull_request.head.ref }}

renovate.json

@@ -33,6 +33,11 @@
       "matchUpdateTypes": ["minor"],
       "matchDepPatterns": [".*@only-patch"],
       "enabled": false
+    },
+    {
+      "description": "Add 'renovate/auto-regenerate' label to a PR if it changes kustomize files to trigger regenerate_on_deps_bump.yaml workflow.",
+      "matchManagers": ["kustomize"],
+      "addLabels": ["renovate/auto-regenerate"]
     }
   ]
 }