Add file arg (#201)

Author: byrnedo

.github/workflows/build.yml

@@ -332,6 +332,7 @@ jobs:
           build-args: VERSION=${{ github.ref_name }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          file: ./ContainerFile
           cache-from: type=gha
           cache-to: type=gha,mode=max
           platforms: linux/amd64,linux/arm64