github.com/pwn-term/docker@v0.0.0-20210616085119-6e977cce2565/moby/daemon/images/image.go (about)

     1  package images // import "github.com/docker/docker/daemon/images"
     2  
     3  import (
     4  	"fmt"
     5  
     6  	"github.com/containerd/containerd/platforms"
     7  	"github.com/pkg/errors"
     8  
     9  	"github.com/docker/distribution/reference"
    10  	"github.com/docker/docker/errdefs"
    11  	"github.com/docker/docker/image"
    12  	specs "github.com/opencontainers/image-spec/specs-go/v1"
    13  )
    14  
    15  // ErrImageDoesNotExist is error returned when no image can be found for a reference.
    16  type ErrImageDoesNotExist struct {
    17  	ref reference.Reference
    18  }
    19  
    20  func (e ErrImageDoesNotExist) Error() string {
    21  	ref := e.ref
    22  	if named, ok := ref.(reference.Named); ok {
    23  		ref = reference.TagNameOnly(named)
    24  	}
    25  	return fmt.Sprintf("No such image: %s", reference.FamiliarString(ref))
    26  }
    27  
    28  // NotFound implements the NotFound interface
    29  func (e ErrImageDoesNotExist) NotFound() {}
    30  
    31  // GetImage returns an image corresponding to the image referred to by refOrID.
    32  func (i *ImageService) GetImage(refOrID string, platform *specs.Platform) (retImg *image.Image, retErr error) {
    33  	defer func() {
    34  		if retErr != nil || retImg == nil || platform == nil {
    35  			return
    36  		}
    37  
    38  		imgPlat := specs.Platform{
    39  			OS:           retImg.OS,
    40  			Architecture: retImg.Architecture,
    41  			Variant:      retImg.Variant,
    42  		}
    43  		p := *platform
    44  		// Note that `platforms.Only` will fuzzy match this for us
    45  		// For example: an armv6 image will run just fine an an armv7 CPU, without emulation or anything.
    46  		if !platforms.Only(p).Match(imgPlat) {
    47  			// This allows us to tell clients that we don't have the image they asked for
    48  			// Where this gets hairy is the image store does not currently support multi-arch images, e.g.:
    49  			//   An image `foo` may have a multi-arch manifest, but the image store only fetches the image for a specific platform
    50  			//   The image store does not store the manifest list and image tags are assigned to architecture specific images.
    51  			//   So we can have a `foo` image that is amd64 but the user requested armv7. If the user looks at the list of images.
    52  			//   This may be confusing.
    53  			//   The alternative to this is to return a errdefs.Conflict error with a helpful message, but clients will not be
    54  			//   able to automatically tell what causes the conflict.
    55  			retErr = errdefs.NotFound(errors.Errorf("image with reference %s was found but does not match the specified platform: wanted %s, actual: %s", refOrID, platforms.Format(p), platforms.Format(imgPlat)))
    56  			return
    57  		}
    58  	}()
    59  	ref, err := reference.ParseAnyReference(refOrID)
    60  	if err != nil {
    61  		return nil, errdefs.InvalidParameter(err)
    62  	}
    63  	namedRef, ok := ref.(reference.Named)
    64  	if !ok {
    65  		digested, ok := ref.(reference.Digested)
    66  		if !ok {
    67  			return nil, ErrImageDoesNotExist{ref}
    68  		}
    69  		id := image.IDFromDigest(digested.Digest())
    70  		if img, err := i.imageStore.Get(id); err == nil {
    71  			return img, nil
    72  		}
    73  		return nil, ErrImageDoesNotExist{ref}
    74  	}
    75  
    76  	if digest, err := i.referenceStore.Get(namedRef); err == nil {
    77  		// Search the image stores to get the operating system, defaulting to host OS.
    78  		id := image.IDFromDigest(digest)
    79  		if img, err := i.imageStore.Get(id); err == nil {
    80  			return img, nil
    81  		}
    82  	}
    83  
    84  	// Search based on ID
    85  	if id, err := i.imageStore.Search(refOrID); err == nil {
    86  		img, err := i.imageStore.Get(id)
    87  		if err != nil {
    88  			return nil, ErrImageDoesNotExist{ref}
    89  		}
    90  		return img, nil
    91  	}
    92  
    93  	return nil, ErrImageDoesNotExist{ref}
    94  }