Export an image

Get a tarball containing all images and metadata for a repository.

If name is a specific name and tag (e.g. ubuntu:latest), then only that image (and its parents) are returned. If name is an image ID, similarly only that image (and its parents) are returned, but with the exclusion of the repositories file in the tarball, as there were no image names referenced.

Image tarball format

An image tarball contains one directory per image layer (named using its long ID), each containing these files:

• VERSION: currently 1.0 - the file format version
• json: detailed layer information, similar to docker inspect layer_id
• layer.tar: A tarfile containing the filesystem changes in this layer

The layer.tar file contains aufs style .wh..wh.aufs files and directories for storing attribute changes and deletions.

If the tarball defines a repository, the tarball should also include a repositories file at the root that contains a list of repository and tag names mapped to layer IDs.

{
  "hello-world": {
    "latest": "565a9d68a73f6706862bfe8409a7f659776d4d60a8d096eb4a3cbce6999cc2a1"
  }
}