github.com/lusis/distribution@v2.0.1+incompatible/registry/handlers/layer.go (about)

     1  package handlers
     2  
     3  import (
     4  	"net/http"
     5  
     6  	"github.com/docker/distribution"
     7  	ctxu "github.com/docker/distribution/context"
     8  	"github.com/docker/distribution/digest"
     9  	"github.com/docker/distribution/registry/api/v2"
    10  	"github.com/gorilla/handlers"
    11  )
    12  
    13  // layerDispatcher uses the request context to build a layerHandler.
    14  func layerDispatcher(ctx *Context, r *http.Request) http.Handler {
    15  	dgst, err := getDigest(ctx)
    16  	if err != nil {
    17  
    18  		if err == errDigestNotAvailable {
    19  			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    20  				w.WriteHeader(http.StatusNotFound)
    21  				ctx.Errors.Push(v2.ErrorCodeDigestInvalid, err)
    22  			})
    23  		}
    24  
    25  		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    26  			ctx.Errors.Push(v2.ErrorCodeDigestInvalid, err)
    27  		})
    28  	}
    29  
    30  	layerHandler := &layerHandler{
    31  		Context: ctx,
    32  		Digest:  dgst,
    33  	}
    34  
    35  	return handlers.MethodHandler{
    36  		"GET":  http.HandlerFunc(layerHandler.GetLayer),
    37  		"HEAD": http.HandlerFunc(layerHandler.GetLayer),
    38  	}
    39  }
    40  
    41  // layerHandler serves http layer requests.
    42  type layerHandler struct {
    43  	*Context
    44  
    45  	Digest digest.Digest
    46  }
    47  
    48  // GetLayer fetches the binary data from backend storage returns it in the
    49  // response.
    50  func (lh *layerHandler) GetLayer(w http.ResponseWriter, r *http.Request) {
    51  	ctxu.GetLogger(lh).Debug("GetImageLayer")
    52  	layers := lh.Repository.Layers()
    53  	layer, err := layers.Fetch(lh.Digest)
    54  
    55  	if err != nil {
    56  		switch err := err.(type) {
    57  		case distribution.ErrUnknownLayer:
    58  			w.WriteHeader(http.StatusNotFound)
    59  			lh.Errors.Push(v2.ErrorCodeBlobUnknown, err.FSLayer)
    60  		default:
    61  			lh.Errors.Push(v2.ErrorCodeUnknown, err)
    62  		}
    63  		return
    64  	}
    65  
    66  	handler, err := layer.Handler(r)
    67  	if err != nil {
    68  		ctxu.GetLogger(lh).Debugf("unexpected error getting layer HTTP handler: %s", err)
    69  		lh.Errors.Push(v2.ErrorCodeUnknown, err)
    70  		return
    71  	}
    72  
    73  	handler.ServeHTTP(w, r)
    74  }