If the package you’re using stays up to date and doesn’t require much setup, you could plug a dockerTools.buildLayeredImage into the imageFile attribute. The name and the tag in the built image should match what’s in the image attribute. An example (busybox is only included for debugging):

        image = "my-calibre-web:latest";
        imageFile = pkgs.dockerTools.buildLayeredImage {
          name = "my-calibre-web";
          tag = "latest";
          contents = [ pkgs.busybox ];
          config.Cmd = [
            "${pkgs.calibre-web}/bin/calibre-web"
            "-p"
            "/config/app.db"
            "-g"
            "/config/gdrive.db"
            "-i"
            "0.0.0.0"
          ];
        };