Bring the content service into the containerd API. This allows the
content store to be coordinated in the containerd daemon with minimal
effort. For the most part, this API follows the conventions and behavior
of the existing content store implementation with a few caveats.
Specifically, we remove the object oriented transaction mechanism in
favor of a very rich `Write` call.
Pains are taken to reduce race conditions around when having multiple
writers to a single piece of content. Clients should be able to race
towards getting a write lock on a reference, then wait on each other.
For the most part, this should be generically pluggable to allow
implementations of the content store to be swapped out.
We'll follow this up with an implementation to validate the model.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This is not really a service like the other rpcs that we expose so lets
change the import paths for it.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
After trying to explain the complexities of developing with protobuf, I
have now created a command that correctly calculates the import paths
for each package and runs the protobuf command.
The Makefile has been updated accordingly, expect we now no longer use
`go generate`. A new target `protos` has been defined. We alias the two,
for the lazy. We leave `go generate` in place for cases where we will
actually use `go generate`.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
