actions: automatic upstream rebase

.github/workflows/sync.yaml

@@ -0,0 +1,51 @@
+name: Rebase Upstream
+on:
+  schedule:
+    - cron: '0 0 * * 0'
+  workflow_dispatch:
+
+jobs:
+  sync:
+    name: Rebase, build, and push image
+    runs-on: ubuntu-latest
+
+    env:
+      IMAGE_NAME: ${{ github.repository }}
+      REGISTRY: ghcr.io
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 10
+
+      - uses: imba-tjd/rebase-upstream-action@master
+        with:
+          upstream: poseidon/fleetlock
+          branch: main
+
+      - name: Build Image
+        id: build-image
+        uses: redhat-actions/buildah-build@v2
+        with:
+          image: ${{ env.IMAGE_NAME }}
+          tags: latest ${{ github.sha }}
+          containerfiles: |
+            ./Dockerfile
+
+      - name: Log in to the GitHub Container registry
+        if: github.event_name != 'pull_request'
+        id: login-to-ghcr
+        uses: redhat-actions/podman-login@v1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Push to GitHub Container Repository
+        if: github.event_name != 'pull_request'
+        id: push-to-ghcr
+        uses: redhat-actions/push-to-registry@v2
+        with:
+          image: ${{ steps.build-image.outputs.image }}
+          tags: ${{ steps.build-image.outputs.tags }}
+          registry: ${{ env.REGISTRY }}