The v2 registry will act as a pull-through cache, and needs to be
handled differently by the client to the v1 registry mirror.
See docker/distribution#459 for details
Configuration
Only one v2 registry can be configured as a mirror. Acceptable configurations
in this chanage are: 0...n v1 mirrors or 1 v2 mirror. A mixture of v1 and v2
mirrors is considered an error.
Pull
If a v2 mirror is configured, all pulls are redirected to that mirror. The
mirror will serve the content locally or attempt a pull from the upstream mirror,
cache it locally, and then serve to the client.
Push
If an image is tagged to a mirror, it will be pushed to the mirror and be
stored locally there. Otherwise, images are pushed to the hub. This is
unchanged behavior.
Signed-off-by: Richard Scothern <richard.scothern@gmail.com>