| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/containerd/containerd/errdefs | Package errdefs defines the common errors used throughout containerd packages. |
| github.com/opencontainers/go-digest | Package digest provides a generalized type to opaquely represent message digests and their operations within the registry. |
| github.com/pkg/errors | Package errors provides simple error handling primitives. |
| io | Package io provides basic interfaces to I/O primitives. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |