Various improvements motivated by early real-world use in engine code
under development:
- Make `WithDigest` return `Canonical`, since the return value always
has a name and a digest.
- Introduce a `NamedTagged` type, which can be used for strongly typing
cases where something must have a name and a tag.
- Rename `ParseNamed` to `WithName`, and create a
`ParseNamed` that accepts tags and digests (returning a `Named` type).
The new `ParseNamed` makes code using the reference package much less
verbose, since typical use cases require a name, and this is an
additional type assertion and error case after every `Parse` call.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
These functions allow a Named type to be combined with a tag or a
digest. WithTag will replace the ImageReference function in
github.com/docker/docker/utils as the Docker Engine transitions to the
reference package.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Since reference itself may be represented by multiple types which implement the reference inteface, serialization can lead to ambiguous type which cannot be deserialized.
Field wraps the reference object to ensure that the correct type is always deserialized, requiring an extra unwrap of the reference after deserialization.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
There seems to be a need for a type that represents a way of pointing
to an image, irrespective of the implementation.
This patch defines a Reference interface and provides 3 implementations:
- TagReference: when only a tag is provided
- DigestReference: when a digest (according to the digest package) is
provided, can include optional tag as well
Validation of references are purely syntactic.
There is also a strong type for tags, analogous to digests, as well
as a strong type for Repository from which clients can access the
hostname alone, or the repository name without the hostname, or both
together via the String() method.
For Repository, the files names.go and names_test.go were moved from
the v2 package.
Signed-off-by: Tibor Vass <tibor@docker.com>
