Fix "oras" OCI client compatibility (#34666) (#34671)

Backport #34666 by wxiaoguang Fix #25846 1. the ImageConfig can be empty, fall back to default 2. the blob size can be empty, it still needs "Content-Length" header Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

Author: GiteaBot

modules/packages/container/metadata.go

@@ -4,6 +4,7 @@
 package container
 
 import (
+"errors"
 "fmt"
 "io"
 "strings"
@@ -83,7 +84,8 @@ func ParseImageConfig(mt string, r io.Reader) (*Metadata, error) {
 
 func parseOCIImageConfig(r io.Reader) (*Metadata, error) {
 var image oci.Image
-if err := json.NewDecoder(r).Decode(&image); err != nil {
+// EOF means empty input, still use the default data
+if err := json.NewDecoder(r).Decode(&image); err != nil && !errors.Is(err, io.EOF) {
 return nil, err
 }
 

modules/packages/container/metadata_test.go

@@ -11,6 +11,7 @@ import (
 
 oci "github.com/opencontainers/image-spec/specs-go/v1"
 "github.com/stretchr/testify/assert"
+"github.com/stretchr/testify/require"
 )
 
 func TestParseImageConfig(t *testing.T) {
@@ -59,3 +60,9 @@ func TestParseImageConfig(t *testing.T) {
 assert.Equal(t, projectURL, metadata.ProjectURL)
 assert.Equal(t, repositoryURL, metadata.RepositoryURL)
 }
+
+func TestParseOCIImageConfig(t *testing.T) {
+metadata, err := parseOCIImageConfig(strings.NewReader(""))
+require.NoError(t, err)
+assert.Equal(t, &Metadata{Type: TypeOCI, Platform: DefaultPlatform, ImageLayers: []string{}}, metadata)
+}

routers/api/packages/container/container.go

@@ -21,6 +21,7 @@ import (
 "code.gitea.io/gitea/modules/httplib"
 "code.gitea.io/gitea/modules/json"
 "code.gitea.io/gitea/modules/log"
+"code.gitea.io/gitea/modules/optional"
 packages_module "code.gitea.io/gitea/modules/packages"
 container_module "code.gitea.io/gitea/modules/packages/container"
 "code.gitea.io/gitea/modules/setting"
@@ -50,7 +51,7 @@ type containerHeaders struct {
 Range string
 Location string
 ContentType string
-ContentLength int64
+ContentLength optional.Option[int64]
 }
 
 // https://github.com/opencontainers/distribution-spec/blob/main/spec.md#legacy-docker-support-http-headers
@@ -64,8 +65,8 @@ func setResponseHeaders(resp http.ResponseWriter, h *containerHeaders) {
 if h.ContentType != "" {
 resp.Header().Set("Content-Type", h.ContentType)
 }
-if h.ContentLength != 0 {
-resp.Header().Set("Content-Length", strconv.FormatInt(h.ContentLength, 10))
+if h.ContentLength.Has() {
+resp.Header().Set("Content-Length", strconv.FormatInt(h.ContentLength.Value(), 10))
 }
 if h.UploadUUID != "" {
 resp.Header().Set("Docker-Upload-Uuid", h.UploadUUID)
@@ -505,7 +506,7 @@ func HeadBlob(ctx *context.Context) {
 
 setResponseHeaders(ctx.Resp, &containerHeaders{
 ContentDigest: blob.Properties.GetByName(container_module.PropertyDigest),
-ContentLength: blob.Blob.Size,
+ContentLength: optional.Some(blob.Blob.Size),
 Status: http.StatusOK,
 })
 }
@@ -644,7 +645,7 @@ func HeadManifest(ctx *context.Context) {
 setResponseHeaders(ctx.Resp, &containerHeaders{
 ContentDigest: manifest.Properties.GetByName(container_module.PropertyDigest),
 ContentType: manifest.Properties.GetByName(container_module.PropertyMediaType),
-ContentLength: manifest.Blob.Size,
+ContentLength: optional.Some(manifest.Blob.Size),
 Status: http.StatusOK,
 })
 }
@@ -708,14 +709,14 @@ func serveBlob(ctx *context.Context, pfd *packages_model.PackageFileDescriptor)
 headers := &containerHeaders{
 ContentDigest: pfd.Properties.GetByName(container_module.PropertyDigest),
 ContentType: pfd.Properties.GetByName(container_module.PropertyMediaType),
-ContentLength: pfd.Blob.Size,
+ContentLength: optional.Some(pfd.Blob.Size),
 Status: http.StatusOK,
 }
 
 if u != nil {
 headers.Status = http.StatusTemporaryRedirect
 headers.Location = u.String()
-headers.ContentLength = 0 // do not set Content-Length for redirect responses
+headers.ContentLength = optional.None[int64]() // do not set Content-Length for redirect responses
 setResponseHeaders(ctx.Resp, headers)
 return
 }

tests/integration/api_packages_container_test.go

@@ -7,6 +7,7 @@ import (
 "bytes"
 "crypto/sha256"
 "encoding/base64"
+"encoding/hex"
 "fmt"
 "net/http"
 "strconv"
@@ -623,6 +624,22 @@ func TestPackageContainer(t *testing.T) {
 assert.Equal(t, blobContent, resp.Body.Bytes())
 })
 
+t.Run("GetBlob/Empty", func(t *testing.T) {
+defer tests.PrintCurrentTest(t)()
+emptyDigestBuf := sha256.Sum256(nil)
+emptyDigest := "sha256:" + hex.EncodeToString(emptyDigestBuf[:])
+req := NewRequestWithBody(t, "POST", fmt.Sprintf("%s/blobs/uploads?digest=%s", url, emptyDigest), strings.NewReader("")).AddTokenAuth(userToken)
+MakeRequest(t, req, http.StatusCreated)
+
+req = NewRequest(t, "HEAD", fmt.Sprintf("%s/blobs/%s", url, emptyDigest)).AddTokenAuth(userToken)
+resp := MakeRequest(t, req, http.StatusOK)
+assert.Equal(t, "0", resp.Header().Get("Content-Length"))
+
+req = NewRequest(t, "GET", fmt.Sprintf("%s/blobs/%s", url, emptyDigest)).AddTokenAuth(userToken)
+resp = MakeRequest(t, req, http.StatusOK)
+assert.Equal(t, "0", resp.Header().Get("Content-Length"))
+})
+
 t.Run("GetTagList", func(t *testing.T) {
 defer tests.PrintCurrentTest(t)()