Support pull by digest, for images that have previously been built

cmd/buildpack/main.go

@@ -71,10 +71,15 @@ func (s *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	switch {
 	case path == "": // API Version check.
 		w.Header().Set("Docker-Distribution-API-Version", "registry/2.0")
+	case strings.Contains(path, "/blobs/"),
+		strings.Contains(path, "/manifests/sha256:"):
+		// Extract requested blob digest and redirect to serve it from GCS.
+		// If it doesn't exist, this will return 404.
+		parts := strings.Split(r.URL.Path, "/")
+		digest := parts[len(parts)-1]
+		serve.Blob(w, r, digest)
 	case strings.Contains(path, "/manifests/"):
 		s.serveBuildpackManifest(w, r)
-	case strings.Contains(path, "/blobs/"):
-		serve.Blob(w, r)
 	default:
 		serve.Error(w, serve.ErrNotFound)
 	}
@@ -149,7 +154,7 @@ func (s *server) serveBuildpackManifest(w http.ResponseWriter, r *http.Request)
 	}
 
 	// Serve the manifest.
-	serve.Manifest(w, img)
+	serve.Manifest(w, r, img)
 }
 
 type cachedManifest struct {

cmd/ko/main.go

@@ -59,10 +59,15 @@ func (s *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		// API Version check.
 		w.Header().Set("Docker-Distribution-API-Version", "registry/2.0")
 		return
-	case strings.HasPrefix(path, "ko/") && strings.Contains(path, "/manifests/"):
+	case strings.Contains(path, "/blobs/"),
+		strings.Contains(path, "/manifests/sha256:"):
+		// Extract requested blob digest and redirect to serve it from GCS.
+		// If it doesn't exist, this will return 404.
+		parts := strings.Split(r.URL.Path, "/")
+		digest := parts[len(parts)-1]
+		serve.Blob(w, r, digest)
+	case strings.Contains(path, "/manifests/"):
 		s.serveKoManifest(w, r)
-	case strings.HasPrefix(path, "ko/") && strings.Contains(path, "/blobs/"):
-		serve.Blob(w, r)
 	default:
 		serve.Error(w, serve.ErrNotFound)
 	}
@@ -119,5 +124,5 @@ func (s *server) serveKoManifest(w http.ResponseWriter, r *http.Request) {
 		serve.Error(w, serve.ErrInvalid)
 		return
 	}
-	serve.Manifest(w, img)
+	serve.Manifest(w, r, img)
 }

cmd/random/main.go

@@ -42,10 +42,15 @@ func (s *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		// API Version check.
 		w.Header().Set("Docker-Distribution-API-Version", "registry/2.0")
 		return
+	case strings.Contains(path, "/blobs/"),
+		strings.Contains(path, "/manifests/sha256:"):
+		// Extract requested blob digest and redirect to serve it from GCS.
+		// If it doesn't exist, this will return 404.
+		parts := strings.Split(r.URL.Path, "/")
+		digest := parts[len(parts)-1]
+		serve.Blob(w, r, digest)
 	case strings.Contains(path, "/manifests/"):
 		s.serveRandomManifest(w, r)
-	case strings.Contains(path, "/blobs/"):
-		serve.Blob(w, r)
 	default:
 		serve.Error(w, serve.ErrNotFound)
 	}
@@ -77,5 +82,5 @@ func (s *server) serveRandomManifest(w http.ResponseWriter, r *http.Request) {
 		serve.Error(w, err)
 		return
 	}
-	serve.Manifest(w, img)
+	serve.Manifest(w, r, img)
 }

pkg/serve/serve.go

@@ -8,7 +8,6 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
-	"strings"
 
 	"cloud.google.com/go/storage"
 	"github.com/google/go-containerregistry/pkg/v1"
@@ -17,16 +16,12 @@ import (
 
 const bucket = "kontainme"
 
-func Blob(w http.ResponseWriter, r *http.Request) {
+func Blob(w http.ResponseWriter, r *http.Request, digest string) {
-	// Extract requested blob digest and redirect to serve it from GCS.
-	// If it doesn't exist, this will return 404.
-	parts := strings.Split(r.URL.Path, "/")
-	digest := parts[len(parts)-1]
 	url := fmt.Sprintf("https://storage.googleapis.com/%s/blobs/%s", bucket, digest)
 	http.Redirect(w, r, url, http.StatusSeeOther)
 }
 
-func writeBlob(h v1.Hash, rc io.ReadCloser) error {
+func writeBlob(h v1.Hash, rc io.ReadCloser, contentType string) error {
 	ctx := context.Background() // TODO
 	client, err := storage.NewClient(ctx)
 	if err != nil {
@@ -38,6 +33,7 @@ func writeBlob(h v1.Hash, rc io.ReadCloser) error {
 	w := client.Bucket(bucket).Object(fmt.Sprintf("blobs/%s", h)).
 		If(storage.Conditions{DoesNotExist: true}).
 		NewWriter(ctx)
+	w.ObjectAttrs.ContentType = contentType
 	if _, err := io.Copy(w, rc); err != nil {
 		if herr, ok := err.(*googleapi.Error); ok && herr.Code == http.StatusPreconditionFailed {
 			return nil
@@ -56,28 +52,29 @@ func writeBlob(h v1.Hash, rc io.ReadCloser) error {
 		}
 		return fmt.Errorf("w.Close: %v", err)
 	}
+	log.Printf("Wrote blob %s", h.String())
 	return nil
 }
 
 // ServeManifest writes config and layer blobs for the image, then serves the
 // manifest contents pointing to those blobs.
-func Manifest(w http.ResponseWriter, img v1.Image) {
+func Manifest(w http.ResponseWriter, r *http.Request, img v1.Image) {
 	// Write config blob for later serving.
 	ch, err := img.ConfigName()
 	if err != nil {
-		log.Printf("ERROR (serveManifest ConfigName): %s", err)
+		log.Printf("ERROR (serveManifest ConfigName): %v", err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 	cb, err := img.RawConfigFile()
 	if err != nil {
-		log.Printf("ERROR (serveManifest RawConfigFile): %s", err)
+		log.Printf("ERROR (serveManifest RawConfigFile): %v", err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 	log.Printf("writing config blob %q", ch)
-	if err := writeBlob(ch, ioutil.NopCloser(bytes.NewReader(cb))); err != nil {
+	if err := writeBlob(ch, ioutil.NopCloser(bytes.NewReader(cb)), ""); err != nil {
-		log.Printf("ERROR (serveManifest writeBlob): %s", err)
+		log.Printf("ERROR (serveManifest writeBlob): %v", err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
@@ -85,48 +82,56 @@ func Manifest(w http.ResponseWriter, img v1.Image) {
 	// Write layer blobs for later serving.
 	layers, err := img.Layers()
 	if err != nil {
-		log.Printf("ERROR (serveManifest Layers): %s", err)
+		log.Printf("ERROR (serveManifest Layers): %v", err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 	for _, l := range layers {
 		rc, err := l.Compressed()
 		if err != nil {
-			log.Printf("ERROR (serveManifest l.Compressed): %s", err)
+			log.Printf("ERROR (serveManifest l.Compressed): %v", err)
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 		lh, err := l.Digest()
 		if err != nil {
-			log.Printf("ERROR (serveManifest l.Digest): %s", err)
+			log.Printf("ERROR (serveManifest l.Digest): %v", err)
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 		log.Printf("writing layer blob %q", lh)
-		if err := writeBlob(lh, rc); err != nil {
+		if err := writeBlob(lh, rc, ""); err != nil {
-			log.Printf("ERROR (serveManifest writeBlob): %s", err)
+			log.Printf("ERROR (serveManifest writeBlob): %v", err)
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 	}
 
-	// Serve the manifest.
+	// Write the manifest as a blob.
 	b, err := img.RawManifest()
 	if err != nil {
-		log.Printf("ERROR (serveManifest RawManifest): %s", err)
+		log.Printf("ERROR (serveManifest RawManifest): %v", err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 	mt, err := img.MediaType()
 	if err != nil {
-		log.Printf("ERROR (serveManifest MediaType): %s", err)
+		log.Printf("ERROR (serveManifest MediaType): %v", err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-	w.Header().Set("Content-Type", string(mt))
+	digest, err := img.Digest()
-	if _, err := io.Copy(w, bytes.NewReader(b)); err != nil {
+	if err != nil {
-		log.Printf("ERROR (serveManifest Copy): %s", err)
+		log.Printf("ERROR (serveManifest Digest): %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
+	if err := writeBlob(digest, ioutil.NopCloser(bytes.NewReader(b)), string(mt)); err != nil {
+		log.Printf("ERROR (serveManifest writeBlob): %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	// Redirect to manifest blob.
+	Blob(w, r, digest.String())
 	fmt.Printf("Served manifest: %s", string(b))
 }