Files
moby/client/image_pull.go
Sebastiaan van Stijn 0823d76ec5 client: keep image refs in canonical format where possible
Using "familiarname" (e.g. "ubuntu") should be mostly done for presenting
image refernces to the user, but internally, we should use the canonical
format where possible ("docker.io/library/ubuntu").

There's still many places where we use the familiar (short) form, but
let's start with not converting references in the client.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2025-03-09 16:52:21 +01:00

65 lines
2.0 KiB
Go

package client // import "github.com/docker/docker/client"
import (
"context"
"io"
"net/url"
"strings"
"github.com/distribution/reference"
"github.com/docker/docker/api/types/image"
"github.com/docker/docker/errdefs"
)
// ImagePull requests the docker host to pull an image from a remote registry.
// It executes the privileged function if the operation is unauthorized
// and it tries one more time.
// It's up to the caller to handle the io.ReadCloser and close it properly.
//
// FIXME(vdemeester): there is currently used in a few way in docker/docker
// - if not in trusted content, ref is used to pass the whole reference, and tag is empty
// - if in trusted content, ref is used to pass the reference name, and tag for the digest
func (cli *Client) ImagePull(ctx context.Context, refStr string, options image.PullOptions) (io.ReadCloser, error) {
ref, err := reference.ParseNormalizedNamed(refStr)
if err != nil {
return nil, err
}
query := url.Values{}
query.Set("fromImage", ref.Name())
if !options.All {
query.Set("tag", getAPITagFromNamedRef(ref))
}
if options.Platform != "" {
query.Set("platform", strings.ToLower(options.Platform))
}
resp, err := cli.tryImageCreate(ctx, query, options.RegistryAuth)
if errdefs.IsUnauthorized(err) && options.PrivilegeFunc != nil {
newAuthHeader, privilegeErr := options.PrivilegeFunc(ctx)
if privilegeErr != nil {
return nil, privilegeErr
}
resp, err = cli.tryImageCreate(ctx, query, newAuthHeader)
}
if err != nil {
return nil, err
}
return resp.Body, nil
}
// getAPITagFromNamedRef returns a tag from the specified reference.
// This function is necessary as long as the docker "server" api expects
// digests to be sent as tags and makes a distinction between the name
// and tag/digest part of a reference.
func getAPITagFromNamedRef(ref reference.Named) string {
if digested, ok := ref.(reference.Digested); ok {
return digested.Digest().String()
}
ref = reference.TagNameOnly(ref)
if tagged, ok := ref.(reference.Tagged); ok {
return tagged.Tag()
}
return ""
}