A light weight overlay implementation that emits working mounts is
demonstrated. One can prepare and commit changes. The diffs are
correctly held on disk.
The next step from here is to implement the changes methods and ensure
that we can work with the docker registry API.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
We define the approach and API of the LayerManipulator. It provides a
model for a bare bones graph driver using a simplified snapshotting
model. Callers Prepare and Commit diff paths to build up a tree of
interelated layers, all without being coupled to the layer diff format
or an image runtime.
Signed-off-by: Stephen J Day <stephen.day@docker.com>