ci: runs-on auf ubuntu-latest (passt zu registriertem Runner)

.gitea/workflows/docker.yml

@@ -5,27 +5,41 @@ on:
     branches: [main]
   workflow_dispatch:
 
+env:
+  REGISTRY: git.jfritzsche.de
+  IMAGE_PREFIX: git.jfritzsche.de/${{ github.repository_owner }}
+
 jobs:
-  build-and-push:
-    # Läuft auf dem self-hosted Runner (Docker muss auf dem Host installiert sein).
-    runs-on: self-hosted
+  docker:
+    name: Docker – Build & Push (Packages)
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Log in to Gitea Container Registry
-        run: echo "${{ secrets.REGISTRY_TOKEN }}" | docker login git.jfritzsche.de -u jf --password-stdin
+      - name: An der Gitea-Container-Registry anmelden
+        run: >
+          echo "${{ secrets.REGISTRY_TOKEN }}" |
+          docker login "$REGISTRY" -u "${{ github.repository_owner }}" --password-stdin
 
-      - name: Build
-        run: |
-          docker build \
-            -t git.jfritzsche.de/jf/jf-homepage:latest \
-            -t git.jfritzsche.de/jf/jf-homepage:${{ github.sha }} .
+      - name: Image bauen
+        run: >
+          docker build .
+          -t "$IMAGE_PREFIX/jf-homepage:latest"
+          -t "$IMAGE_PREFIX/jf-homepage:${{ github.sha }}"
 
-      - name: Push
+      - name: Image in die Registry pushen
         run: |
-          docker push git.jfritzsche.de/jf/jf-homepage:latest
-          docker push git.jfritzsche.de/jf/jf-homepage:${{ github.sha }}
+          docker push "$IMAGE_PREFIX/jf-homepage:latest"
+          docker push "$IMAGE_PREFIX/jf-homepage:${{ github.sha }}"
+
+      - name: Veraltete Image-Tags auf dem Runner aufräumen
+        run: >
+          docker images --format '{{.Repository}}:{{.Tag}}'
+          | grep "^$IMAGE_PREFIX/jf-homepage:"
+          | grep -v -e ':latest$' -e ':${{ github.sha }}$'
+          | xargs -r docker rmi
+          || true
 
       - name: Logout
-        run: docker logout git.jfritzsche.de
+        run: docker logout "$REGISTRY"