In addition to apt and npm, I would like to see docker image distribution powered by IPFS. It really feels stupid to pull images from a central registry sitting on the other side of the globe when the image is already present in the next node in your kubernetes cluster.
There is a big issue, that ipfs uses its own hash mechanism (hash of protobuf of dag), while registries (and most other existing content based distribution mechanisms) use sha256 hashes of the whole content.
So you can't simply interop between the two without some sort of lookup to convert hash functions. It is hugely frustrating, as basically different content based distribution mechanisms cant work together.
In theory docker image registries support pluggable hash functions, although it is not clear to me that the ipfs function is even very well defined outside its own code. We could start to add a second hash calculation to every registry operation, but it would be a performance hit which some users would not like.
(tree based content hashes that allow parallelisation are nice, but the ipfs one is very ipfs specific and more complex than it needs to be I think).
