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.
This changeset move the Manifest type into the storage package to make the type
accessible to client and registry without import cycles. The structure of the
manifest was also changed to accuratle reflect the stages of the signing
process. A straw man Manifest.Sign method has been added to start testing this
concept out but will probably be accompanied by the more import
SignedManifest.Verify method as the security model develops.
This is probably the start of a concerted effort to consolidate types across
the client and server portions of the code base but we may want to see how such
a handy type, like the Manifest and SignedManifest, would work in docker core.
This updates API error codes to coincide with changes to the proposal. Mostly,
redundant error codes were merged and missing ones were added. The set in the
main errors.go file will flow back into the specification.
A test case has been added to ensure ErrorCodeUnknown is included in marshaled
json.
This has Errors implement the error interface, allowing it to pose as an error
itself. Use of this in the server may be minimal, for now, but it's useful for
passing around opaque client errors.
A method, PushErr, has also been add to allow arbitrary errors to be passed
into the Errors list. This keeps the errors list flexible, allowing the app to
collect and errors before we have codes properly mapped.
