Merge pull request #3136 from ctalledo/reworked-fix-for-moby-45458

Output correct image ID when using Docker with the containerd-snapshotter

Author: tonistiigi

build/build.go

@@ -525,7 +525,6 @@ func BuildWithResultHandler(ctx context.Context, nodes []builder.Node, opts map[
 							}
 						}
 					}
-
 					node := dp.Node().Driver
 					if node.IsMobyDriver() {
 						for _, e := range so.Exports {
@@ -561,6 +560,14 @@ func BuildWithResultHandler(ctx context.Context, nodes []builder.Node, opts map[
 							}
 						}
 					}
+					// if prefer-image-digest is set in the solver options, remove the image
+					// config digest from the exporter's response
+					for _, e := range so.Exports {
+						if e.Attrs["prefer-image-digest"] == "true" {
+							delete(rr.ExporterResponse, exptypes.ExporterImageConfigDigestKey)
+							break
+						}
+					}
 					return nil
 				})
 			}

build/opt.go

@@ -237,6 +237,11 @@ func toSolveOpt(ctx context.Context, node builder.Node, multiDriver bool, opt *O
 					opt.Exports[i].Output = func(_ map[string]string) (io.WriteCloser, error) {
 						return w, nil
 					}
+					// if docker is using the containerd snapshotter, prefer to export the image digest
+					// (rather than the image config digest). See https://github.com/moby/moby/issues/45458.
+					if features[dockerutil.OCIImporter] {
+						opt.Exports[i].Attrs["prefer-image-digest"] = "true"
+					}
 				}
 			} else if !nodeDriver.Features(ctx)[driver.DockerExporter] {
 				return nil, nil, notSupported(driver.DockerExporter, nodeDriver, "https://docs.docker.com/go/build-exporters/")

tests/build.go

@@ -399,18 +399,25 @@ func testImageIDOutput(t *testing.T, sb integration.Sandbox) {
 
 	require.Equal(t, dgst.String(), strings.TrimSpace(stdout.String()))
 
+	// read the md.json file
 	dt, err = os.ReadFile(filepath.Join(targetDir, "md.json"))
 	require.NoError(t, err)
 
 	type mdT struct {
+		Digest       string `json:"containerimage.digest"`
 		ConfigDigest string `json:"containerimage.config.digest"`
 	}
+
 	var md mdT
 	err = json.Unmarshal(dt, &md)
 	require.NoError(t, err)
 
 	require.NotEmpty(t, md.ConfigDigest)
-	require.Equal(t, dgst, digest.Digest(md.ConfigDigest))
+	require.NotEmpty(t, md.Digest)
+
+	// verify the image ID output is correct
+	// XXX: improve this by checking that it's one of the two expected digests depending on the scenario.
+	require.Contains(t, []digest.Digest{digest.Digest(md.ConfigDigest), digest.Digest(md.Digest)}, dgst)
 }
 
 func testBuildMobyFromLocalImage(t *testing.T, sb integration.Sandbox) {