| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/docker/distribution/context | Package context provides several utilities for working with Go's context in http requests. |
| github.com/docker/distribution/registry/auth | Package auth defines a standard interface for request access controllers. |
| golang.org/x/net/context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| net/http | Package http provides HTTP client and server implementations. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |