pkgs.dockerTools.buildNixShellImage

The following is the current implementation of this function.

buildNixShellImage = { drv, compressor ? "gz", ... }@args:
    let
      stream = streamNixShellImage (builtins.removeAttrs args ["compressor"]);
      compress = compressorForImage compressor drv.name;
    in
    runCommand "${drv.name}-env.tar${compress.ext}"
      {
        inherit (stream) imageName;
        passthru = { inherit (stream) imageTag; };
        nativeBuildInputs = compress.nativeInputs;
      } "${stream} | ${compress.compress} > $out";