In support of making the storage API ready for supporting notifications and
mirroring, we've begun the process of paring down the storage model. The
process started by creating a central Registry interface. From there, the
common name argument on the LayerService and ManifestService was factored into
a Repository interface. The rest of the changes directly follow from this.
An interface wishlist was added, suggesting a direction to take the registry
package that should support the distribution project's future goals. As these
objects move out of the storage package and we implement a Registry backed by
the http client, these design choices will start getting validation.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This change refactors the storage backend to use the new path layout. To
facilitate this, manifest storage has been separated into a revision store and
tag store, supported by a more general blob store. The blob store is a hybrid
object, effectively providing both small object access, keyed by content
address, as well as methods that can be used to manage and traverse links to
underlying blobs. This covers common operations used in the revision store and
tag store, such as linking and traversal. The blob store can also be updated to
better support layer reading but this refactoring has been left for another
day.
The revision store and tag store support the manifest store's compound view of
data. These underlying stores provide facilities for richer access models, such
as content-addressable access and a richer tagging model. The highlight of this
change is the ability to sign a manifest from different hosts and have the
registry merge and serve those signatures as part of the manifest package.
Various other items, such as the delegate layer handler, were updated to more
directly use the blob store or other mechanism to fit with the changes.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
It was probably ill-advised to couple manifest signing and verification to
their respective types. This changeset simply changes them from methods to
functions. These might not even be in this package in the future.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Because manifests and their signatures are a discrete component of the
registry, we are moving the definitions into a separate package. This causes us
to lose some test coverage, but we can fill this in shortly. No changes have
been made to the external interfaces, but they are likely to come.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This change updates the backend storage package that consumes StorageDriver to
use the new Stat call, over CurrentSize. It also makes minor updates for using
WriteStream and ReadStream.
This diff removes a few early outs that caused errors to be unreported and
catches a missed error case for signature verification from libtrust. More work
needs to be done around ensuring consistent error handling but this is enough
to make the API work correctly.
To provide rich error reporting during manifest pushes, the storage layers
verifyManifest stage has been modified to provide the necessary granularity.
Along with this comes with a partial shift to explicit error types, which
represents a small move in larger refactoring of error handling. Signature
methods from libtrust have been added to the various Manifest types to clean up
the verification code.
A primitive deletion implementation for manifests has been added. It only
deletes the manifest file and doesn't attempt to add some of the richer
features request, such as layer cleanup.
This change implements the first pass at image manifest storage on top of the
storagedriver. Very similar to LayerService, its much simpler due to less
complexity of pushing and pulling images.
Various components are still missing, such as detailed error reporting on
missing layers during verification, but the base functionality is present.
