Layer metadata storage has not been implemented outside of the layer
store and will be deprecated by containerd metadata storage. To prepare
for this and freeze the current metadata storage, remove the exported
interface and make it internal to the layer store.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
The `digest` data type, used throughout docker for image verification
and identity, has been broken out into `opencontainers/go-digest`. This
PR updates the dependencies and moves uses over to the new type.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Layer store manages read-only and read-write layers on a union file system.
Read only layers are always referenced by content addresses.
Read-write layer identifiers are handled by the caller but upon registering
its difference, the committed read-only layer will be referenced by content
hash.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
