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Include headers when serving blob through proxy

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In commit 17952924f3 we updated ServeBlob() to use an io.MultiWriter to
write simultaneously to the local store and the HTTP response.

However, copyContent was using a type assertion to only add headers if
the io.Writer was a http.ResponseWriter. Therefore, this change caused
us to stop sending the expected headers (i.e. Content-Length, Etag,
etc.) on the first request for a blob.

Resolve the issue by explicitly passing in http.Header and setting it
unconditionally.

Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
This commit is contained in:
Mikel Rychliski 2024-01-26 18:56:45 -05:00
parent 9b3eac8f08
commit 041824555c
2 changed files with 20 additions and 12 deletions
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20
registry/proxy/proxyblobstore.go
View file

@ -33,22 +33,20 @@ var inflight = make(map[digest.Digest]struct{})
// mu protects inflight
var mu sync.Mutex
func setResponseHeaders(w http.ResponseWriter, length int64, mediaType string, digest digest.Digest) {
w.Header().Set("Content-Length", strconv.FormatInt(length, 10))
w.Header().Set("Content-Type", mediaType)
w.Header().Set("Docker-Content-Digest", digest.String())
w.Header().Set("Etag", digest.String())
func setResponseHeaders(h http.Header, length int64, mediaType string, digest digest.Digest) {
h.Set("Content-Length", strconv.FormatInt(length, 10))
h.Set("Content-Type", mediaType)
h.Set("Docker-Content-Digest", digest.String())
h.Set("Etag", digest.String())
}
func (pbs *proxyBlobStore) copyContent(ctx context.Context, dgst digest.Digest, writer io.Writer) (distribution.Descriptor, error) {
func (pbs *proxyBlobStore) copyContent(ctx context.Context, dgst digest.Digest, writer io.Writer, h http.Header) (distribution.Descriptor, error) {
desc, err := pbs.remoteStore.Stat(ctx, dgst)
if err != nil {
return distribution.Descriptor{}, err
}
if w, ok := writer.(http.ResponseWriter); ok {
setResponseHeaders(w, desc.Size, desc.MediaType, dgst)
}
setResponseHeaders(h, desc.Size, desc.MediaType, dgst)
remoteReader, err := pbs.remoteStore.Open(ctx, dgst)
if err != nil {
@ -102,7 +100,7 @@ func (pbs *proxyBlobStore) ServeBlob(ctx context.Context, w http.ResponseWriter,
// Will return the blob from the remote store directly.
// TODO Maybe we could reuse the these blobs are serving remotely and caching locally.
mu.Unlock()
_, err := pbs.copyContent(ctx, dgst, w)
_, err := pbs.copyContent(ctx, dgst, w, w.Header())
return err
}
inflight[dgst] = struct{}{}
@ -122,7 +120,7 @@ func (pbs *proxyBlobStore) ServeBlob(ctx context.Context, w http.ResponseWriter,
// Serving client and storing locally over same fetching request.
// This can prevent a redundant blob fetching.
multiWriter := io.MultiWriter(w, bw)
desc, err := pbs.copyContent(ctx, dgst, multiWriter)
desc, err := pbs.copyContent(ctx, dgst, multiWriter, w.Header())
if err != nil {
return err
}

12
registry/proxy/proxyblobstore_test.go
View file

@ -448,12 +448,22 @@ func testProxyStoreServe(t *testing.T, te *testEnv, numClients int) {
return
}
bodyBytes := w.Body.Bytes()
resp := w.Result()
bodyBytes, err := io.ReadAll(resp.Body)
resp.Body.Close()
if err != nil {
t.Errorf(err.Error())
return
}
localDigest := digest.FromBytes(bodyBytes)
if localDigest != remoteBlob.Digest {
t.Errorf("Mismatching blob fetch from proxy")
return
}
if resp.Header.Get("Docker-Content-Digest") != localDigest.String() {
t.Errorf("Mismatching digest in response header")
return
}
desc, err := te.store.localStore.Stat(te.ctx, remoteBlob.Digest)
if err != nil {