build: read body response to check for erroneous image export to docker

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

util/dockerutil/client.go

@@ -46,17 +46,24 @@ func (c *Client) LoadImage(ctx context.Context, name string, status progress.Wri
 	w = &waitingWriter{
 		PipeWriter: pw,
 		f: func() {
-			resp, err := dapi.ImageLoad(ctx, pr, false)
-			defer close(done)
-			if err != nil {
+			handleErr := func(err error) {
 				pr.CloseWithError(err)
 				w.mu.Lock()
 				w.err = err
 				w.mu.Unlock()
+			}
+
+			resp, err := dapi.ImageLoad(ctx, pr, false)
+			defer close(done)
+			if err != nil {
+				handleErr(err)
 				return
 			}
+
 			prog := progress.WithPrefix(status, "", false)
-			progress.FromReader(prog, "importing to docker", resp.Body)
+			if err := fromReader(prog, "importing to docker", resp.Body); err != nil {
+				handleErr(err)
+			}
 		},
 		done:   done,
 		cancel: cancel,

util/dockerutil/progress.go

@@ -1,15 +1,19 @@
-package progress
+package dockerutil
 
 import (
+	"errors"
 	"io"
 	"time"
 
+	"github.com/docker/buildx/util/progress"
+	"github.com/docker/cli/cli/streams"
+	"github.com/docker/docker/pkg/jsonmessage"
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/identity"
 	"github.com/opencontainers/go-digest"
 )
 
-func FromReader(w Writer, name string, rc io.ReadCloser) {
+func fromReader(w progress.Writer, name string, rc io.ReadCloser) error {
 	dgst := digest.FromBytes([]byte(identity.NewID()))
 	tm := time.Now()
 
@@ -23,7 +27,12 @@ func FromReader(w Writer, name string, rc io.ReadCloser) {
 		Vertexes: []*client.Vertex{&vtx},
 	})
 
-	_, err := io.Copy(io.Discard, rc)
+	err := jsonmessage.DisplayJSONMessagesToStream(rc, streams.NewOut(io.Discard), nil)
+	if err != nil {
+		if jerr, ok := err.(*jsonmessage.JSONError); ok {
+			err = errors.New(jerr.Message)
+		}
+	}
 
 	tm2 := time.Now()
 	vtx2 := vtx
@@ -34,4 +43,5 @@ func FromReader(w Writer, name string, rc io.ReadCloser) {
 	w.Write(&client.SolveStatus{
 		Vertexes: []*client.Vertex{&vtx2},
 	})
+	return err
 }