CRFS: Container Registry Filesystem

One reason that reading the bytes directly from the source on demand is somewhat non-trivial is that container images are, somewhat regrettably, represented by tar.gz files, and tar files are unindexed, and gzip streams are not seekable. TODO: examples

When mounting an image, the FUSE filesystem makes a couple Docker Registry HTTP API requests to the container registry to get the metadata for the container and all its layers. Ideally container runtimes would support something like this whole scheme natively, but in the meantime a workaround is that when converting an image into stargz format, the converter tool can also produce an image variant that only has metadata (environment, entrypoints, etc) and no file contents.

Source: github.com