The normalization was being inconsistently applied causing a
failure to match some platforms in manifest lists.
Fix the matcher and normalization to be more consistent and
add changes to parser to prevent the defaulted variants from being
set in the platform structure.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
Matching support is now implemented in the platforms package. The
`Parse` function now returns a matcher object that can be used to
match OCI platform specifications. We define this as an interface to
allow the creation of helpers oriented around platform selection.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
For supporting selection of images and runtimes in the containerized
world, there is thin support for selecting objects by platform. This
package defines a syntax to display to users that can express specific
platforms in addition to wild cards for matching platforms.
The plan is to extend this to provide support for parsing flag
arguments and displaying platform types for images. This package will
also provide a configurable matcher to allow match of platforms against
arbitrary targets, invariant to the Go compilation.
The internals are based the OCI Image Spec model.
This changeset is being submitted for feedback on the approach before
this gets larger. Specifically, review the unit tests and raise any
concerns.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
