I've got an existing build system that creates (among other things) container images. Due to the nature of their contents, they are suitable for running on practically any containerization toolset one might care to use.
Now I've got some users who want to load them into Docker. Ok, that works fine, except that each revision of the container image imports separately.
The users would like to take advantage of the space-saving capabilities of Docker layers to deduplicate data between versions.
I could, of course, instantiate the previous image, and then use rsync or similar to update it and then commit it (and that's what I'll do if I have to) but that seems like an awfully clunky workflow.
Is there some piece of functionality built into Docker that I'm just not finding that would simplify the process of importing updated image tarballs into an existing image's history? I can find all kinds of resources about pruning and flattening Docker history, but nothing for those of us who manage our image contents via other systems.