| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/distribution/reference | Package reference provides a general type to represent any way of referencing images within the registry. |
| github.com/opencontainers/go-digest | Package digest provides a generalized type to opaquely represent message digests and their operations within the registry. |
| github.com/opencontainers/image-spec/specs-go/v1 | |
| io | Package io provides basic interfaces to I/O primitives. |
| mime | Package mime implements parts of the MIME spec. |
| net/http | Package http provides HTTP client and server implementations. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| time | Package time provides functionality for measuring and displaying time. |