Use registry token fallback for Docker push

.gitea/workflows/docker-build.yml

@@ -67,14 +67,31 @@ jobs:
           docker images "${IMAGE_REPO}"
 
       - name: Login to Gitea Container Registry
-        if: gitea.event_name == 'push' && gitea.ref == 'refs/heads/main'
+        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+        shell: bash
         run: |
-          echo "${{ secrets.GITEA_TOKEN }}" | docker login "${REGISTRY}" \
+          REGISTRY_USERNAME="${{ secrets.REGISTRY_USERNAME }}"
-            --username "${{ gitea.actor }}" \
+          REGISTRY_PASSWORD="${{ secrets.REGISTRY_TOKEN }}"
+
+          if [ -z "${REGISTRY_USERNAME}" ]; then
+            REGISTRY_USERNAME="${{ github.actor }}"
+          fi
+
+          if [ -z "${REGISTRY_PASSWORD}" ]; then
+            REGISTRY_PASSWORD="${{ secrets.GITHUB_TOKEN }}"
+          fi
+
+          if [ -z "${REGISTRY_PASSWORD}" ]; then
+            echo "REGISTRY_TOKEN or GITHUB_TOKEN is required for docker login." >&2
+            exit 1
+          fi
+
+          echo "${REGISTRY_PASSWORD}" | docker login "${REGISTRY}" \
+            --username "${REGISTRY_USERNAME}" \
             --password-stdin
 
       - name: Push Docker image
-        if: gitea.event_name == 'push' && gitea.ref == 'refs/heads/main'
+        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
         run: |
           docker push "${IMAGE_TAG}"
           docker push "${IMAGE_LATEST}"