Package pull forked from https://github.com/containerd/containerd/blob/v1.4.3/cmd/ctr/commands/content/fetch.go.

Package push derived from https://github.com/containerd/containerd/blob/v1.4.3/cmd/ctr/commands/images/push.go.

EnsureImage ensures the image.

FilterByLabel filters images based on labels given in `filters`.

FilterByReference filters images using references given in `filters`.

FilterDangling filters dangling images (or keeps if `dangling` == false).

FilterImages returns images in `labelImages` that are created before MAX(beforeImages.CreatedAt) and after MIN(sinceImages.CreatedAt).

GetExistingImage returns the specified image if exists in containerd.

ParseFilters parse filter strings.

ParseRepoTag parses raw `imgName` to repository and tag.

PullImage pulls an image using the specified resolver.

ReadImageConfig reads the config spec (`application/vnd.oci.image.config.v1+json`) for img.platform from content store.

ReadIndex returns image index, or nil for non-indexed image.

ReadManifest returns the manifest for img.platform, or nil if no manifest was found.

ResolveDigest resolves `rawRef` and returns its descriptor digest.

UnpackedImageSize is the size of the unpacked snapshots.

Filter types supported to filter images.

Filter types supported to filter images.

Filter types supported to filter images.

Filter types supported to filter images.

Filter types supported to filter images.

EnsuredImage contains the image existed in containerd and its metadata.

Filters contains all types of filters to filter images.

PullMode is either one of "always", "missing", "never".