Remove gogoproto.customtype

gogoproto.customtype is used to have go-digest.Digest instead of string.
While it is convinient, protoc-gen-go doesn't support the extension
and that blocks #6564.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

content/proxy/content_reader.go

@@ -36,7 +36,7 @@ func (ra *remoteReaderAt) Size() int64 {
 
 func (ra *remoteReaderAt) ReadAt(p []byte, off int64) (n int, err error) {
 	rr := &contentapi.ReadContentRequest{
-		Digest: ra.digest,
+		Digest: ra.digest.String(),
 		Offset: off,
 		Size_:  int64(len(p)),
 	}

content/proxy/content_store.go

@@ -42,7 +42,7 @@ func NewContentStore(client contentapi.ContentClient) content.Store {
 
 func (pcs *proxyContentStore) Info(ctx context.Context, dgst digest.Digest) (content.Info, error) {
 	resp, err := pcs.client.Info(ctx, &contentapi.InfoRequest{
-		Digest: dgst,
+		Digest: dgst.String(),
 	})
 	if err != nil {
 		return content.Info{}, errdefs.FromGRPC(err)
@@ -81,7 +81,7 @@ func (pcs *proxyContentStore) Walk(ctx context.Context, fn content.WalkFunc, fil
 
 func (pcs *proxyContentStore) Delete(ctx context.Context, dgst digest.Digest) error {
 	if _, err := pcs.client.Delete(ctx, &contentapi.DeleteContentRequest{
-		Digest: dgst,
+		Digest: dgst.String(),
 	}); err != nil {
 		return errdefs.FromGRPC(err)
 	}
@@ -119,7 +119,7 @@ func (pcs *proxyContentStore) Status(ctx context.Context, ref string) (content.S
 		UpdatedAt: status.UpdatedAt,
 		Offset:    status.Offset,
 		Total:     status.Total,
-		Expected:  status.Expected,
+		Expected:  digest.Digest(status.Expected),
 	}, nil
 }
 
@@ -152,7 +152,7 @@ func (pcs *proxyContentStore) ListStatuses(ctx context.Context, filters ...strin
 			UpdatedAt: status.UpdatedAt,
 			Offset:    status.Offset,
 			Total:     status.Total,
-			Expected:  status.Expected,
+			Expected:  digest.Digest(status.Expected),
 		})
 	}
 
@@ -200,7 +200,7 @@ func (pcs *proxyContentStore) negotiate(ctx context.Context, ref string, size in
 		Action:   contentapi.WriteActionStat,
 		Ref:      ref,
 		Total:    size,
-		Expected: expected,
+		Expected: expected.String(),
 	}); err != nil {
 		return nil, 0, err
 	}
@@ -215,7 +215,7 @@ func (pcs *proxyContentStore) negotiate(ctx context.Context, ref string, size in
 
 func infoToGRPC(info content.Info) contentapi.Info {
 	return contentapi.Info{
-		Digest:    info.Digest,
+		Digest:    info.Digest.String(),
 		Size_:     info.Size,
 		CreatedAt: info.CreatedAt,
 		UpdatedAt: info.UpdatedAt,
@@ -225,7 +225,7 @@ func infoToGRPC(info content.Info) contentapi.Info {
 
 func infoFromGRPC(info contentapi.Info) content.Info {
 	return content.Info{
-		Digest:    info.Digest,
+		Digest:    digest.Digest(info.Digest),
 		Size:      info.Size_,
 		CreatedAt: info.CreatedAt,
 		UpdatedAt: info.UpdatedAt,

content/proxy/content_writer.go

@@ -45,7 +45,7 @@ func (rw *remoteWriter) send(req *contentapi.WriteContentRequest) (*contentapi.W
 	if err == nil {
 		// try to keep these in sync
 		if resp.Digest != "" {
-			rw.digest = resp.Digest
+			rw.digest = digest.Digest(resp.Digest)
 		}
 	}
 
@@ -92,7 +92,7 @@ func (rw *remoteWriter) Write(p []byte) (n int, err error) {
 
 	rw.offset += int64(n)
 	if resp.Digest != "" {
-		rw.digest = resp.Digest
+		rw.digest = digest.Digest(resp.Digest)
 	}
 	return
 }
@@ -115,7 +115,7 @@ func (rw *remoteWriter) Commit(ctx context.Context, size int64, expected digest.
 		Action:   contentapi.WriteActionCommit,
 		Total:    size,
 		Offset:   rw.offset,
-		Expected: expected,
+		Expected: expected.String(),
 		Labels:   base.Labels,
 	})
 	if err != nil {
@@ -126,11 +126,12 @@ func (rw *remoteWriter) Commit(ctx context.Context, size int64, expected digest.
 		return fmt.Errorf("unexpected size: %v != %v", resp.Offset, size)
 	}
 
-	if expected != "" && resp.Digest != expected {
+	actual := digest.Digest(resp.Digest)
+	if expected != "" && actual != expected {
 		return fmt.Errorf("unexpected digest: %v != %v", resp.Digest, expected)
 	}
 
-	rw.digest = resp.Digest
+	rw.digest = actual
 	rw.offset = resp.Offset
 	return nil
 }