| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| crypto/sha512 | Package sha512 implements the SHA-384, SHA-512, SHA-512/224, and SHA-512/256 hash algorithms as defined in FIPS 180-4. |
| crypto/x509 | Package x509 implements a subset of the X.509 standard. |
| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| 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/docker/distribution | Package distribution will define the interfaces for the components of docker distribution. |
| github.com/docker/distribution/manifest | |
| github.com/docker/distribution/reference | Package reference is deprecated, and has moved to github.com/distribution/reference. |
| github.com/docker/libtrust | Package libtrust provides an interface for managing authentication and authorization using public key cryptography. |
| github.com/opencontainers/go-digest | Package digest provides a generalized type to opaquely represent message digests and their operations within the registry. |
| github.com/sirupsen/logrus | Package logrus is a structured logger for Go, completely API compatible with the standard library logger. |
| time | Package time provides functionality for measuring and displaying time. |