github.com/DaoCloud/dao@v0.0.0-20161212064103-c3dbfd13ee36/distribution/pull_v2_windows.go (about)

     1  // +build windows
     2  
     3  package distribution
     4  
     5  import (
     6  	"encoding/json"
     7  	"fmt"
     8  	"net/http"
     9  	"os"
    10  
    11  	"github.com/docker/distribution"
    12  	"github.com/docker/distribution/context"
    13  	"github.com/docker/distribution/manifest/schema1"
    14  	"github.com/docker/distribution/manifest/schema2"
    15  	"github.com/docker/distribution/registry/client/transport"
    16  	"github.com/docker/docker/image"
    17  )
    18  
    19  func detectBaseLayer(is image.Store, m *schema1.Manifest, rootFS *image.RootFS) error {
    20  	v1img := &image.V1Image{}
    21  	if err := json.Unmarshal([]byte(m.History[len(m.History)-1].V1Compatibility), v1img); err != nil {
    22  		return err
    23  	}
    24  	if v1img.Parent == "" {
    25  		return fmt.Errorf("Last layer %q does not have a base layer reference", v1img.ID)
    26  	}
    27  	// There must be an image that already references the baselayer.
    28  	for _, img := range is.Map() {
    29  		if img.RootFS.Type == image.TypeLayersWithBase && img.RootFS.BaseLayerID() == v1img.Parent {
    30  			rootFS.BaseLayer = img.RootFS.BaseLayer
    31  			rootFS.Type = image.TypeLayersWithBase
    32  			return nil
    33  		}
    34  	}
    35  	return fmt.Errorf("Invalid base layer %q", v1img.Parent)
    36  }
    37  
    38  var _ distribution.Describable = &v2LayerDescriptor{}
    39  
    40  func (ld *v2LayerDescriptor) Descriptor() distribution.Descriptor {
    41  	if ld.src.MediaType == schema2.MediaTypeForeignLayer && len(ld.src.URLs) > 0 {
    42  		return ld.src
    43  	}
    44  	return distribution.Descriptor{}
    45  }
    46  
    47  func (ld *v2LayerDescriptor) open(ctx context.Context) (distribution.ReadSeekCloser, error) {
    48  	if len(ld.src.URLs) == 0 {
    49  		blobs := ld.repo.Blobs(ctx)
    50  		return blobs.Open(ctx, ld.digest)
    51  	}
    52  
    53  	var (
    54  		err error
    55  		rsc distribution.ReadSeekCloser
    56  	)
    57  
    58  	// Find the first URL that results in a 200 result code.
    59  	for _, url := range ld.src.URLs {
    60  		rsc = transport.NewHTTPReadSeeker(http.DefaultClient, url, nil)
    61  		_, err = rsc.Seek(0, os.SEEK_SET)
    62  		if err == nil {
    63  			break
    64  		}
    65  		rsc.Close()
    66  		rsc = nil
    67  	}
    68  	return rsc, err
    69  }