Two ways to do this: - properly during the save with `dockerode`, see branch [`image_tags_tarball`](https://github.com/o2r-project/o2r-muncher/tree/image_tags_tarball) and https://github.com/apocas/dockerode/issues/470 - updating the tarball after it was saved manually, manipulate the `manifest.json` file with npm package `tar`