As the number of repos and layers increases, the greater the probability
that layers are duplicated. We dedupe using hard links when content is
the same. This is intended to be purely a storage layer optimization.
Access control when available is orthogonal this optimization.
Add a durable cache to help speed up layer lookups.
Update README.
Add more unit tests.
Clients today expect the repo to clean up if there are unused blobs, not to
manually delete things they think are unused. Let's do that, and use
umoci's code to do it since it's tested and works.
v2: also run GC on update as well as delete
v3: fix up error return paths needing two args
Signed-off-by: Serge Hallyn <shallyn@cisco.com>
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Fixes issue #67.
As per dist spec, DELETE of a image manifest can only be done with
digest as <reference> param. Previously, tags were being allowed as
well. This is not conformant to the spec.
