I love seeing folks learn that container images are just fancy tar files and JSON and are therefore buildable by normal tools.
Along my own journey of demystification I made a few toy container image registries over the years that generated and served container images from nothing but the URL itself:
https://ko.kontain.me builds a go application on demand and serves it atop a minimal base image
https://apko.kontain.me builds a base image containing packages listed in the URL, again on demand.
The latest addition, https://git.kontain.me serves an image with the specified git repo already checked out in the image.
None of these should be used for anything serious but they were fun to make and play with. :)
random.kontain.me has been uncharacteristically useful in debugging image caching scenarios.
I sometimes wonder why there aren't more bespoke container tools (like yours). Would people be willing to pay for stuff like what you have built, if someone took the time to "productionize" it? Or is there no market?
I don't know any scenario where I'd need any of that, but I love such things regardless.
About git.kontain.me - what if I'd like to setup my own copy of such a service and would like it to work with a non-public git repo, how to pass credentials? Since you support only cloning over https (btw, why not over ssh as well?) - one could use an URL of format user:pass@host:port/path/to/repo, would that work?