github.com/kaisenlinux/docker.io@v0.0.0-20230510090727-ea55db55fac7/engine/client/image_pull.go (about)

     1  package client // import "github.com/docker/docker/client"
     2  
     3  import (
     4  	"context"
     5  	"io"
     6  	"net/url"
     7  	"strings"
     8  
     9  	"github.com/docker/distribution/reference"
    10  	"github.com/docker/docker/api/types"
    11  	"github.com/docker/docker/errdefs"
    12  )
    13  
    14  // ImagePull requests the docker host to pull an image from a remote registry.
    15  // It executes the privileged function if the operation is unauthorized
    16  // and it tries one more time.
    17  // It's up to the caller to handle the io.ReadCloser and close it properly.
    18  //
    19  // FIXME(vdemeester): there is currently used in a few way in docker/docker
    20  // - if not in trusted content, ref is used to pass the whole reference, and tag is empty
    21  // - if in trusted content, ref is used to pass the reference name, and tag for the digest
    22  func (cli *Client) ImagePull(ctx context.Context, refStr string, options types.ImagePullOptions) (io.ReadCloser, error) {
    23  	ref, err := reference.ParseNormalizedNamed(refStr)
    24  	if err != nil {
    25  		return nil, err
    26  	}
    27  
    28  	query := url.Values{}
    29  	query.Set("fromImage", reference.FamiliarName(ref))
    30  	if !options.All {
    31  		query.Set("tag", getAPITagFromNamedRef(ref))
    32  	}
    33  	if options.Platform != "" {
    34  		query.Set("platform", strings.ToLower(options.Platform))
    35  	}
    36  
    37  	resp, err := cli.tryImageCreate(ctx, query, options.RegistryAuth)
    38  	if errdefs.IsUnauthorized(err) && options.PrivilegeFunc != nil {
    39  		newAuthHeader, privilegeErr := options.PrivilegeFunc()
    40  		if privilegeErr != nil {
    41  			return nil, privilegeErr
    42  		}
    43  		resp, err = cli.tryImageCreate(ctx, query, newAuthHeader)
    44  	}
    45  	if err != nil {
    46  		return nil, err
    47  	}
    48  	return resp.body, nil
    49  }
    50  
    51  // getAPITagFromNamedRef returns a tag from the specified reference.
    52  // This function is necessary as long as the docker "server" api expects
    53  // digests to be sent as tags and makes a distinction between the name
    54  // and tag/digest part of a reference.
    55  func getAPITagFromNamedRef(ref reference.Named) string {
    56  	if digested, ok := ref.(reference.Digested); ok {
    57  		return digested.Digest().String()
    58  	}
    59  	ref = reference.TagNameOnly(ref)
    60  	if tagged, ok := ref.(reference.Tagged); ok {
    61  		return tagged.Tag()
    62  	}
    63  	return ""
    64  }