support metadata file with call flag for build and bake commands

Signed-off-by: CrazyMax <[email protected]>

Author: crazy-max

commands/bake.go

@@ -252,13 +252,15 @@ func runBake(ctx context.Context, dockerCli command.Cli, targets []string, in ba
 	if progressMode != progressui.QuietMode && progressMode != progressui.RawJSONMode {
 		desktop.PrintBuildDetails(os.Stderr, printer.BuildRefs(), term)
 	}
-	if callFunc == nil && len(in.metadataFile) > 0 {
+	if len(in.metadataFile) > 0 {
 		dt := make(map[string]interface{})
 		for t, r := range resp {
 			dt[t] = decodeExporterResponse(r.ExporterResponse)
 		}
-		if warnings := printer.Warnings(); len(warnings) > 0 && confutil.MetadataWarningsEnabled() {
-			dt["buildx.build.warnings"] = warnings
+		if callFunc == nil {
+			if warnings := printer.Warnings(); len(warnings) > 0 && confutil.MetadataWarningsEnabled() {
+				dt["buildx.build.warnings"] = warnings
+			}
 		}
 		if err := writeMetadataFile(in.metadataFile, dt); err != nil {
 			return err

commands/build.go

@@ -367,20 +367,23 @@ func runBuild(ctx context.Context, dockerCli command.Cli, options buildOptions)
 			return errors.Wrap(err, "writing image ID file")
 		}
 	}
+	if options.metadataFile != "" {
+		dt := decodeExporterResponse(resp.ExporterResponse)
+		if opts.PrintFunc == nil {
+			if warnings := printer.Warnings(); len(warnings) > 0 && confutil.MetadataWarningsEnabled() {
+				dt["buildx.build.warnings"] = warnings
+			}
+		}
+		if err := writeMetadataFile(options.metadataFile, dt); err != nil {
+			return err
+		}
+	}
 	if opts.PrintFunc != nil {
 		if exitcode, err := printResult(dockerCli.Out(), opts.PrintFunc, resp.ExporterResponse); err != nil {
 			return err
 		} else if exitcode != 0 {
 			os.Exit(exitcode)
 		}
-	} else if options.metadataFile != "" {
-		dt := decodeExporterResponse(resp.ExporterResponse)
-		if warnings := printer.Warnings(); len(warnings) > 0 && confutil.MetadataWarningsEnabled() {
-			dt["buildx.build.warnings"] = warnings
-		}
-		if err := writeMetadataFile(options.metadataFile, dt); err != nil {
-			return err
-		}
 	}
 	return nil
 }
@@ -733,10 +736,16 @@ func writeMetadataFile(filename string, dt interface{}) error {
 func decodeExporterResponse(exporterResponse map[string]string) map[string]interface{} {
 	out := make(map[string]interface{})
 	for k, v := range exporterResponse {
-		dt, err := base64.StdEncoding.DecodeString(v)
-		if err != nil {
-			out[k] = v
-			continue
+		var dt []byte
+		var err error
+		if k == "result.json" {
+			dt = []byte(v)
+		} else {
+			dt, err = base64.StdEncoding.DecodeString(v)
+			if err != nil {
+				out[k] = v
+				continue
+			}
 		}
 		var raw map[string]interface{}
 		if err = json.Unmarshal(dt, &raw); err != nil || len(raw) == 0 {