func NewRegistryPullThroughCache(ctx context.Context, registry distribution.Namespace, driver driver.StorageDriver, config configuration.Proxy) (distribution.Namespace, error)
NewRegistryPullThroughCache creates a registry acting as a pull through cache
Metrics is used to hold metric counters related to the proxy
type Metrics struct { Requests uint64 Hits uint64 Misses uint64 BytesPulled uint64 BytesPushed uint64 }